1,653 research outputs found

    Reactive Oxygen Species: A Key Hallmark of Cardiovascular Disease.

    Full text link
    Cardiovascular diseases (CVDs) have been the prime cause of mortality worldwide for decades. However, the underlying mechanism of their pathogenesis is not fully clear yet. It has been already established that reactive oxygen species (ROS) play a vital role in the progression of CVDs. ROS are chemically unstable reactive free radicals containing oxygen, normally produced by xanthine oxidase, nicotinamide adenine dinucleotide phosphate oxidase, lipoxygenases, or mitochondria or due to the uncoupling of nitric oxide synthase in vascular cells. When the equilibrium between production of free radicals and antioxidant capacity of human physiology gets altered due to several pathophysiological conditions, oxidative stress is induced, which in turn leads to tissue injury. This review focuses on pathways behind the production of ROS, its involvement in various intracellular signaling cascades leading to several cardiovascular disorders (endothelial dysfunction, ischemia-reperfusion, and atherosclerosis), methods for its detection, and therapeutic strategies for treatment of CVDs targeting the sources of ROS. The information generated by this review aims to provide updated insights into the understanding of the mechanisms behind cardiovascular complications mediated by ROS

    Mechanisms and dynamics of the metastable decay in Ar-2(+)

    Get PDF
    A detailed experimental as well as theoretical investigation of the properties of the metastable dissociation Ar-2(+)--\u3eAr++Ar is presented. The mass-analyzed ion kinetic energy (MIKE) scan technique has been performed using a three sector field mass spectrometer. The possible mechanisms of the metastability of Ar-2(+) have been examined and the observed decay process is assigned to the II(1/2)(u)--\u3eI(1/2)(g) bound to continuum radiative transition, in agreement with earlier work. The calculation of the theoretical shape of the kinetic energy release distribution of fragment ions allowed us to construct the theoretical MIKE peak and compare it with the raw experimental data. The accuracy of various sets of potential energy curves for Ar-2(+) is discussed, as well as the way of production of the metastable Ar-2(+)[II(1/2)(u)] electronic state by electron impact. Excellent agreement between the experimental data and theoretical model has been observed. (C) 2004 American Institute of Physics

    Comparative evaluation of microscopy and polymerase chain reaction (PCR) for the diagnosis in suspected malaria patients of Nepal

    Get PDF
    to compare the efficiency of microscopy and PCR for malaria diagnosis in Nepalese context. During July-August 2007, blood samples were collected in glass slides and on filter papers from suspected malaria cases of Kanchanpur, Jhapa and Morang Districts. Sample transportation and storage was done using standard protocol. Microscopy was done at the heath posts in the district in Nepal while Nested PCR using previously standardized primers was carried out at Mahidol University. Among 824 malaria suspected cases, 19.2

    Cr3+ substitution effect on Co-Cu and Cu-Co nano ferrites on structural and morphological properties

    Get PDF
    The Cr3+ substituted Co-Cu (Co0.7Cu0.3Fe2-xCrxO4) and Cu-Co (Cu0.7Co0.3Fe2-xCrxO4) where x = 0.0, 0.05, 0.1, 0.15, 0.2 and 0.25 nano ferrite composite were prepared with the sol-gel approach. Their structural, dc electrical resistivity, and magnetic properties were analyzed. XRD shows the single-phase spinel ferrite. Adding Cr3+ ions decreases the lattice volume and the size of the crystallite respectively. FESEM images show non-spherical particles on a largely uniform surface shape with decreasing grain size on doping Cr3+. The FTIR pattern supports the XRD patterns for spinel ferrite

    A Note on Exploration of Sequence Spaces and Function Spaces on Interval [0,1] for DNA Sequencing

    Get PDF
    In [7] authors studied the sequence spaces and function spaces on interval [0,1]. Further they introduced new sequence spaces by using generalized p-summation method and proved these spaces of sequences and functions are Banach spaces. In this paper we extend the results of authors in [7] by introducing a new basis function and strongly p-summation method

    Diverse Environmental Microbiota as a Tool to Augment Biodiversity in Urban Landscaping Materials

    Get PDF
    Human activities typically lead to simplified urban diversity, which in turn reduces microbial exposure and increases the risk to urban dwellers from non-communicable diseases. To overcome this, we developed a microbial inoculant from forest and agricultural materials that resembles microbiota in organic soils. Three different sand materials (sieved, safety and sandbox) commonly used in playgrounds and other public spaces were enriched with 5 % of the inoculant. Skin microbiota on fingers (identified from bacterial 16S rDNA determined using Illumina MiSeq sequencing) was compared after touching non-enriched and microbial inoculant-enriched sands. Exposure to the non-enriched materials changed the skin bacterial community composition in distinct ways. When the inoculant was added to the materials, the overall shift in community composition was larger and the differences between different sand materials almost disappeared. Inoculant-enriched sand materials increased bacterial diversity and richness but did not affect evenness at the OTU level on skin. The Firmicutes/Bacteroidetes ratio was higher after touching inoculant-enriched compared to non-enriched sand materials. The relative abundance of opportunistic pathogens on skin was 40–50 % before touching sand materials, but dropped to 14 % and 4 % after touching standard and inoculant-enriched sand materials, respectively. When individual genera were analyzed, Pseudomonas sp. and Sphingomonas sp. were more abundant after touching standard, non-enriched sand materials, while only the relative abundance of Chryseobacterium sp. increased after touching the inoculant-enriched materials. As Chryseobacterium is harmless for healthy persons, and as standard landscaping materials and normal skin contain genera that include severe pathogens , the inoculant-enriched materials can be considered safe. Microbial inoculants could be specifically created to increase the proportion of non-pathogenic bacterial taxa and minimize the transfer of pathogenic taxa. We recommend further study into the usability of inoculant-enriched materials and their effects on the bacterial community composition of human skin and on the immune response.Peer reviewe

    On the effectiveness of rotational friction hinge damper to control responses of multi-span simply supported bridge to non-uniform ground motions

    Get PDF
    Base isolation techniques have been extensively used to improve the seismic performance of the bridge structures. The decoupling of the bridge decks from the piers and abutments using rubber isolator could result in significant reduction in seismic forces transmitted to the bridge substructures. However, the isolation devices could also increase the deck displacement and thus enhance the possibility of pounding and unseating damage of bridge decks. Moreover, previous investigations have shown that pounding and unseating damages on isolated bridges exacerbate due to the spatial variation in earthquake ground motions. Recent earthquakes revealed that isolation bearing could also be damaged due to the excessive movements of decks during large earthquake events. This study proposes the use of rotational friction hinge dampers to mitigate the damages that could be induced by large displacement of bridge decks, particularly focusing on pounding and unseating damages and bearing damages. The device is capable of providing large hysteretic damping and the cost of installing the devices is relatively economical. This article presents numerical investigations on the effectiveness of these devices on a typical Nepalese simply supported bridge subjected to spatially varying ground motions. The results indicate that rotational friction hinge dampers are very effective in mitigating the relative displacement and pounding force, as well as controlling the bearing deformation and pier drift. It is also revealed that the effectiveness of the device is not significantly affected by small changes in the slip forces; thus, small variations in the optimum slip forces during the lifetime of the bridge do not warrant any adjustment or replacement of the device

    Membranes, molecules and biophysics: enhancing monocyte derived dendritic cell (MDDC) immunogenicity for improved anti-cancer therapy

    Get PDF
    Despite great medical advancement in the treatment of cancer, cancer remains a disease of global significance. Chemotherapeutics can be very expensive and drain medical resources at a national level and in some cases the cost of treatment is so great that it prohibits their use by local health authorities. Drug resistance is also a major limiting factor to the successful treatment of cancer with many patients initially responding well but then becoming refractory to treatment with the same drug and in some case may become multi-drug resistant. The immune system is known to be important in the prevention of tumors by eliminating pre-cancerous or cancerous cells. This concept of immune surveillance has largely been super-ceded by the concept of immunoediting whereby the immune system imposes a selective pressure on tumor cells which may either control tumor growth or inadvertently select for tumor cells which have evolved to escape the immune response and which may induce tumor development. Stimulation of the immune system by vaccination offers many benefits in the treatment of cancer. It is highly cost effective and vaccines can be manipulated to include multi-antigens which in some cases may overcome equilibrium (and selective pressure) while also preventing the establishment of reactivated cancer cells, since cancer antigen-specific memory would be induced following the initial vaccination/booster phase. To date studies using vaccination as a treatment for cancer have been a little disappointing, probably due to insufficient level of immunogenicity. In this review we will discuss methods of manipulation of the immune system to increase the anti-cancer activity of dendritic cells in vivo and how monocyte derived dendritic cells may be manipulated ex vivo to provide more robust, patient-specific treatments
    • …
    corecore