670 research outputs found

    Turkey's response to the global economic crisis

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    Turkey was not affected by the financial crisis as much as the advanced economies and managed to rapidly exit the turmoil. The reasons behind the strong response and quick recovery of the Turkish economy were its low country risk and low currency risk premiums. This study shows the foundations of these low risk premiums and compares some measures of these risks of the Turkish economy with peer countries. Second, this paper demonstrates that all of Turkey’s economic sectors were very strong before the crisis and sustained this strength during the course of the crisis. Finally, it discusses the policies that have already been taken and planned to be taken by Turkey’s economic authorities. The government seems to be very determined in keeping fiscal discipline as tight as necessary while not being excessivefinancial crises, global economic crisis, Turkey, economic policies, financial markets

    Bank regulation and supervision and its welfare implications

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    Cataloged from PDF version of article.This study provides a general equilibrium model to explore the welfare implications of bank regulation and supervision (RS). The model supports the basic expectations regarding the positive effects of RS on the growth rate, output, credit, investment, wages and profits; and its negative effects on the interest rate. In addition, RS is observed to lead to a convergence effect. Furthermore, it is observed that the decision of banks to monitor and charge differentiated interest rates to firms depends on the distribution of firm-specific moral hazard rates; bank monitoring increases profits as the distribution of producer type improves. (C) 2011 Elsevier B.V. All rights reserved

    Osteoselection supported by phase separeted polymer blend films

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    Cataloged from PDF version of article.The instability of implants after placement inside the body is one of the main obstacles to clinically succeed in periodontal and orthopedic applications. Adherence of fibroblasts instead of osteoblasts to implant surfaces usually results in formation of scar tissue and loss of the implant. Thus, selective bioadhesivity of osteoblasts is a desired characteristic for implant materials. In this study, we developed osteoselective and biofriendly polymeric thin films fabricated with a simple phase separation method using either homopolymers or various blends of homopolymers and copolymers. As adhesive and proliferative features of cells are highly dependent on the physicochemical properties of the surfaces, substrates with distinct chemical heterogeneity, wettability, and surface topography were developed and assessed for their osteoselective characteristics. Surface characterizations of the fabricated polymer thin films were performed with optical microscopy and SEM, their wettabilities were determined by contact angle measurements, and their surface roughness was measured by profilometry. Long-term adhesion behaviors of cells to polymer thin films were determined by F-actin staining of Saos-2 osteoblasts, and human gingival fibroblasts, HGFs, and their morphologies were observed by SEM imaging. The biocompatibility of the surfaces was also examined through cell viability assay. Our results showed that heterogeneous polypropylene polyethylene/polystyrene surfaces can govern Saos-2 and HGF attachment and organization. Selective adhesion of Saos-2 osteoblasts and inhibited adhesion of HGF cells were achieved on micro-structured and hydrophobic surfaces. This work paves the way for better control of cellular behaviors for adjustment of cell material interactions. © 2014 Wiley Periodicals, Inc

    Turkey's response to the global economic crisis

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    Turkey was not affected by the financial crisis as much as the advanced economies and managed to rapidly exit the turmoil. The reasons behind the strong response and quick recovery of the Turkish economy were its low country risk and low currency risk premiums. This study shows the foundations of these low risk premiums and compares some measures of these risks of the Turkish economy with peer countries. Second, this paper demonstrates that all of Turkey’s economic sectors were very strong before the crisis and sustained this strength during the course of the crisis. Finally, it discusses the policies that have already been taken and planned to be taken by Turkey’s economic authorities. The government seems to be very determined in keeping fiscal discipline as tight as necessary while not being excessiv

    Unlocking the in vitroanti- inflammatory and antidiabetic potential of Polygonum maritimum

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    Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes. Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L. Material and methods: Antioxidant activity was determined (up to 1mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24 h at concentrations up to 100 mu g/mL and antidiabetic potential was assessed by alpha-amylase and alpha-glucosidase inhibition (up to 10 g/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS). Results: The methanol leaf extract had the highest activity against DPPH center dot (IC50 = 26 mu g/mL) and ABTS1(+)center dot (IC50 = 140 mu g FRAP (IC50 = 48 mu g/mL) and CCA (IC50 = 770 mu g/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC50 = 48 mu g/mL). The methanol root (IC50 = 19 mu g/mL) and leaf (IC50 = 29 mu g/mL) extracts strongly inhibited baker's yeast alpha-glucosidase, but LDCM had higher rat's alpha-glucosidase inhibition (IC50 = 2527 mu g/mL) than acarbose (IC50 = 4638 mu g/mL). GC-MS analysis identified beta-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities. Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.XtremeBio project - Foundation for Science and Technology (FCT) [PTDC/MAR-EST/4346/2012]; Portuguese National Budget; FCT [CCMAR/Multi/04326/ 2013, IF/00049/2012, SFRH/BPD/86071/2012, UID/Multi/00612/2013

    X-ray Fluorescence Analysis of Feldspars and Silicate Glass: Effects of Melting Time on Fused Bead Consistency and Volatilisation

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    Reproducible preparation of lithium tetraborate fused beads for XRF analysis of glass and mineral samples is of paramount importance for analytical repeatability. However, as with all glass melting processes, losses due to volatilisation must be taken into account and their effects are not negligible. Here the effects of fused bead melting time have been studied for four Certified Reference Materials (CRM’s: three feldspars, one silicate glass), in terms of their effects on analytical variability and volatilisation losses arising from fused bead preparation. At melting temperatures of 1065 °C, and for feldspar samples, fused bead melting times shorter than approximately 25 min generally gave rise to a greater deviation of the XRF-analysed composition from the certified composition. This variation might be due to incomplete fusion and/or fused bead inhomogeneity but further research is needed. In contrast, the shortest fused bead melting time for the silicate glass CRM gave an XRF-analysed composition closer to the certified values than longer melting times. This may suggest a faster rate of glass-in-glass dissolution and homogenization during fused bead preparation. For all samples, longer melting times gave rise to greater volatilisation losses (including sulphates and halides) during fusion. This was demonstrated by a linear relationship between SO3 mass loss and time1/2, as predicted by a simple diffusion-based model. Iodine volatilisation displays a more complex relationship, suggestive of diffusion plus additional mechanisms. This conclusion may have implications for vitrification of iodine-bearing radioactive wastes. Our research demonstrates that the nature of the sample material impacts on the most appropriate fusion times. For feldspars no less than ~25 min and no more than ~60 min of fusion at 1065 °C, using Li2B4O7 as the fusion medium and in the context of feldspar samples and the automatic fusion equipment used here, strikes an acceptable (albeit non-ideal) balance between the competing factors of fused bead quality, analytical consistency and mitigating volatilisation losses. Conversely, for the silicate glass sample, shorter fusion times of less than ~30 min under the same conditions provided more accurate analyses whilst limiting volatile losses

    Cell penetrating peptide amphiphile integrated liposomal systems for enhanced delivery of anticancer drugs to tumor cells

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    Liposomes have been extensively used as effective nanocarriers, providing better solubility, higher stability and slower release of drugs compared to free drug administration. They are also preferred due to their nontoxic nature as well as their biodegradability and cell membrane mimicking abilities. In this study, we examined noncovalent integration of a cell penetrating arginine-rich peptide amphiphile into a liposomal formulation of negatively charged 1,2-dioleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DOPG) phospholipids in the presence of cholesterol due to its amphipathic character. We studied changes in the physical characteristics (size, surface potential and membrane polarity) of the liposomal membrane, as well as in the encapsulation of hydrophilic and hydrophobic agents due to peptide amphiphile incorporation. The activities of peptide integrated liposomal systems as drug delivery agents were investigated by using anti-cancer drugs, doxorubicin-HCl and paclitaxel. Enhancement in liposomal uptake due to arginine-rich peptide integration, and enhanced efficacy of the drugs were observed with peptide functionalized liposomes compared to free drugs. © 2013 The Royal Society of Chemistry

    Growth and differentiation of prechondrogenic cells on bioactive self-assembled peptide nanofibers

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    Restoration of cartilage defect remains a challenge, as the current treatments are ineffective to return tissue to its health. Thus, developing therapies for treatment of cartilage tissue damage caused by common joint diseases including osteoarthritis, rheumatoid arthritis, and accidents is crucial. Sulfated glycosaminoglycan molecules are vital constituents of both developing and mature cartilage extracellular matrix. The interplay between regulator proteins and glycosaminoglycan molecules has an essential role in coordinating differentiation, expansion, and patterning during cartilage development. In this study, we exploited the functional role of an extracellular matrix on chondrogenic differentiation by imitating extracellular matrix both chemically by imparting functional groups of native glycosaminoglycans and structurally through peptide nanofiber network. For this purpose, sulfonate, carboxylate, and hydroxyl groups were incorporated on self-assembled peptide nanofibers. We observed that when ATDC5 cells were cultured on functional peptide nanofibers, they rapidly aggregated in insulin-free medium and formed cartilage-like nodules and deposited sulfated glycosaminoglycans shown by Safranin-O staining. Moreover, collagen II and aggrecan gene expressions revealed by qRT-PCR were significantly enhanced, which indicated the remarkable bioactive role of this nanofiber system on chondrogenic differentiation. Overall, these results show that glycosaminoglycan mimetic peptide nanofiber system provides a promising platform for cartilage regeneration. © 2012 American Chemical Society

    A One-Piece Lunar Regolith Bag Garage Prototype

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    Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. This Technical Memorandum details the design and construction of a prototype for a one-piece regolith bag unpressurized garage concept and a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. The conceptualization was that a lightweight fabric form be launched from Earth and landed on the lunar surface to be robotically filled with raw lunar regolith. Regolith bag fabric candidates included: Vectran(TM), Nextel(TM), Gore PTFE Fabric(TM), Zylon(TM), Twaron(TM), and Nomex(TM). Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and also performed under cold and elevated temperatures. In some cases, Johnson Space Center lunar simulant (JSC-1) was used in conjunction with testing. A series of preliminary structures was constructed during final prototype design based on the principles of the classic masonry arch. The prototype was constructed of Kevlar(TM) and filled with vermiculite. The structure is free-standing, but has not yet been load tested. Future plans would be to construct higher fidelity prototypes and to conduct appropriate tests of the structure

    Magnetic Tweezers-Based Force Clamp Reveals Mechanically Distinct apCAM Domain Interactions

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    ABSTRACT Cell adhesion molecules of the immunoglobulin superfamily (IgCAMs) play a crucial role in cell-cell interactions during nervous system development and function. The Aplysia CAM (apCAM), an invertebrate IgCAM, shares structural and functional similarities with vertebrate NCAM and therefore has been considered as the Aplysia homolog of NCAM. Despite these similarities, the binding properties of apCAM have not been investigated thus far. Using magnetic tweezers, we applied physiologically relevant, constant forces to apCAM-coated magnetic particles interacting with apCAM-coated model surfaces and characterized the kinetics of bond rupture. The average bond lifetime decreased with increasing external force, as predicted by theoretical considerations. Mathematical simulations suggest that the apCAM homophilic interaction is mediated by two distinct bonds, one involving all five immunoglobulin (Ig)-like domains in an antiparallel alignment and the other involving only two Ig domains. In summary, this study provides biophysical evidence that apCAM undergoes homophilic interactions, and that magnetic tweezers-based, force-clamp measurements provide a rapid and reliable method for characterizing relatively weak CAM interactions
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