296 research outputs found
Synthesis of Iron Oxide Magnetic Nanoparticles: Characterization and its Biomedical Application
In the present time, Iron oxide magnetic nanoparticles (IOMNPs) have paid considerable attention due to their exclusive applications in terms of surface-to-volume ratio, superparamagnetism, high surface area, biosensor, bio-separation, catalysis, and biomedicine. Our goal was to synthesis iron oxide magnetic nanoparticles by chemical route technique. The preparation method had a very large effect on the size, shape, and surface chemistry of the magnetic nanoparticles including their applications. The iron chloride solution was prepared by mixing deionized water with iron chloride tetrahydrate. The synthesized powder was characterized by XRD, UV-vis, SEM, FT-IR, DLS, FL, and TGA techniques. Moreover, antibacterial activity was evaluated using the synthesized IOMNPs against Escherichia coli (A), Pseudomonas (B), Enterobacter (C), Staphylococcus aureus (D), and Bacillus subtilis (E) in the concentration of 0.1 mg and 0.5 mg. The results showed that Bacillus subtilis possess a higher antibacterial activity at the concentration of 0.5 mg comparing the other bacterial species. The outcome of this work would contribute to the present understanding of the biomedical application with the obtained size, shape, and synthesized method
Green Synthesis and Characterization of Antibacterial Studies by Iron Oxide Nanoparticles using Carica papaya Leaf Extract
In present years, the synthesis of iron oxide nanoparticles (IONPs) has established excessive potential in biological applications due to their non-toxic role in biological systems, biocompatibility, and biodegradability. Ongoing research efforts focused on IONPs in the expansion of novel technologies as they can be synthesized with surface modification. Here we have studied the antibacterial effects of IONPs which were synthesized effectively through a green synthesis route by using leaf extract of the Carica papaya plant. The formation of IONPs was confirmed by the color change. The crystallinity of IONPs was determined by XRD and the morphology by using SEM, which showed spherical particles of well-dispersed size. The absorption peak was determined by UV–vis spectroscopy at 390 nm. Average particle size distribution was obtained at 56 nm using PSA. FL spectroscopy indicated the higher emission wavelength by redshift at 641.6 nm. TGA showed that the IONPs are thermally stable up to 200⁰C with no decomposition. The outcome would pave a way for utilizing IONPs for better biomedical application
Synthesis and Characterization of Silver Nanoparticles from Ashyranthus aspera Extract for Antimicrobial Activity Studies
Development of biologically inspired experimental processes for the
synthesis of nanoparticles is evolving into an important branch of
nanotechnology. Plant-mediated synthesis of nanomaterials has been
increasingly gaining popularity due to its eco-friendly nature and
cost-effectiveness. In the present study, we were synthesized silver
(Ag) nanoparticles using aqueous extracts of fresh leaves of
Ashyranthus aspera medicinal plants as bio-reducing agents. UV-Vis
spectrometer used to monitor the reduction of Ag ions and the formation
of AgNPs in the medium. UV-Vis spectra and visual observation showed
that the color of the fresh leaf extracts of Ashyranthus aspera turned
into grayish-brown respectively, after treatment with Ag precursors.
XRD and SEM have been used to investigate the morphology of prepared
AgNPs. The peaks in the XRD pattern are associated with that of the
Face-Centered-Cubic (FCC) form of metallic silver. TGA/DTA results
associated with weight loss and exothermic reaction due to the
desorption of chemisorbed water. FTIR was performed to identify the
functional groups which form a layer covering AgNPs and stabilize the
AgNPs in the medium. Moreover, silver nanoparticles using aqueous leaf
extracts of Ashyranthus aspera were separately tested for their
antibacterial activity against Gram-positive bacteria ( Staphylococcus
aureus ) and Gram-negative bacteria ( Enterobacter ). The results
showed that the bacterial growth was inhibited by the extracts
containing AgNPs Nanoparticles. The biosynthesized nanoparticle was
prepared from Ashyranthus aspera leaf extracts exhibits potential
applications as broad-spectrum antimicrobial agents
He Scores Through a Screen: Mediating Masculinities Through Hockey Video Games
Hockey video games highlight the ways in which the video game medium shapes and conditions the experience of producing and/or performing the sport “in real life.” Indeed, the accumulation of advanced statistics in and through the constant evaluation, measurement, and surveillance which are inherent to video games—and increasingly seen as foundational for sport—reveals important contradictions not only in the way the embodied sport is played and understood, but also in terms of the proofs of masculinity upon which the sport is built. It then becomes clear that the building of masculinity and the empowerment of the character become one and the same. The ludic function reinforces the cultural imperative and vice versa. Thus, our chapter prizes apart the conflation of masculinity with hockey while showing the ways that video game studies can contribute to existing disciplines
Stochastic Gravity: A Primer with Applications
Stochastic semiclassical gravity of the 90's is a theory naturally evolved
from semiclassical gravity of the 70's and 80's. It improves on the
semiclassical Einstein equation with source given by the expectation value of
the stress-energy tensor of quantum matter fields in curved spacetimes by
incorporating an additional source due to their fluctuations. In stochastic
semiclassical gravity the main object of interest is the noise kernel, the
vacuum expectation value of the (operator-valued) stress-energy bi-tensor, and
the centerpiece is the (stochastic) Einstein-Langevin equation. We describe
this new theory via two approaches: the axiomatic and the functional. The
axiomatic approach is useful to see the structure of the theory from the
framework of semiclassical gravity. The functional approach uses the
Feynman-Vernon influence functional and the Schwinger-Keldysh close-time-path
effective action methods which are convenient for computations. It also brings
out the open systems concepts and the statistical and stochastic contents of
the theory such as dissipation, fluctuations, noise and decoherence. We then
describe the application of stochastic gravity to the backreaction problems in
cosmology and black hole physics. Intended as a first introduction to this
subject, this article places more emphasis on pedagogy than completeness.Comment: 46 pages Latex. Intended as a review in {\it Classical and Quantum
Gravity
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BoBBLE: ocean-atmosphere interaction and its impact on the South Asian monsoon
The Bay of Bengal (BoB) plays a fundamental role in controlling the weather systems that make up the South Asian summer monsoon system. In particular,the southern BoB has cooler sea surface temperature (SST) that influence ocean-atmosphere interaction and impact on the monsoon. Compared to the southeast, the southwestern BoB is cooler, more saline, receives much less rain, and is influenced by the Summer Monsoon Current(SMC). To examine the impact of these features on the monsoon, the BoB Boundary Layer Experiment (BoBBLE) was jointly undertaken by India and the UK during June–July 2016. Physical and bio-geochemical observations were made using a CTD, five ocean gliders, a uCTD, a VMP, two ADCPs, Argo floats, drifting buoys, meteorological sensors and upper air radiosonde balloons. The observations were made along a zonal section at 8◦N between 85.3◦E and 89◦E with a 10-day time series at 89◦E, 8◦N. This paper presents the new observed features of the southern BoB from the BoBBLE field program, supported by satellite data. Key results from the BoBBLE field campaign show the Sri Lanka Dome and the SMC in different stages of their seasonal evolution and two freshening events during which salinity decreased in the upper layer leading to the formation of thick barrier layers. BoBBLE observations were taken during a suppressed phase of the intraseasonal oscillation; they captured in detail the warming of the ocean mixed layer and preconditioning of the atmosphere to convection
Masculinities, affect and the (re)place(ment) of stardom in Formula One fan leisure practices
Writing from an autoethnographic perspective, this article explores male leisure practices via the mediated relationships fans enter into with stars. More specifically, my own fandom for Formula One driver Jacques Villeneuve is the locus of study, revealing how this affective investment shapes and furnishes my corresponding leisure practices. Notions of gendered 'performativity' come to the fore, with my own displays evoking, enacting and revealing oscillating performances of masculinity. Moreover, there are interesting gendered dynamics that such fan leisure practices flag in terms of the intersection of female/male relationships and the potential 'fantasy' and/or narcissistic readings that a male fan identifying with and performing as another male sport star afford. Finally, my research reveals paradoxes for contemporary masculinities, with fans reliant upon mediation and commodification to facilitate and sustain their performative roles. © 2011 Taylor & Francis
Schools, families, and social reproduction
Neoliberal educational discourse across the Global North is marked by an increasing homogeneity, but this masks significant socio-spatial differences in the enactment of policy. The authors focus on four facets of roll-out neoliberalism in English education policy that have expanded the function of primary schools, and redrawn the boundary between state and family responsibilities. Specifically, these are increased state support for: (1) working parenthood through provision of wraparound childcare; (2) parent-child relationships through school-led provision of parenting classes; (3) parental involvement in children’s learning; and (4) child development through schools’ fostering of extracurricular activities. The politics of policies that both enhance state responsibility for, and influence in, matters that were previously within the purview of families are complex. The collective impact of these developments has been both to reform how the work of daily and generational social reproduction is done, and to reshape the social reproduction of a classed and gendered society
Altered T Cell Memory and Effector Cell Development in Chronic Lymphatic Filarial Infection That Is Independent of Persistent Parasite Antigen
Chronic lymphatic filarial (LF) infection is associated with suppression of parasite-specific T cell responses that persist even following elimination of infection. While several mechanisms have been implicated in mediating this T cell specific downregulation, a role for alterations in the homeostasis of T effector and memory cell populations has not been explored. Using multiparameter flow cytometry, we investigated the role of persistent filarial infection on the maintenance of T cell memory in patients from the filarial-endemic Cook Islands. Compared to filarial-uninfected endemic normals (EN), microfilaria (mf) positive infected patients (Inf) had a reduced CD4 central memory (TCM) compartment. In addition, Inf patients tended to have more effector memory cells (TEM) and fewer effector cells (TEFF) than did ENs giving significantly smaller TEFF ∶ TEM ratios. These contracted TCM and TEFF populations were still evident in patients previously mf+ who had cleared their infection (CLInf). Moreover, the density of IL-7Rα, necessary for T memory cell maintenance (but decreased in T effector cells), was significantly higher on memory cells of Inf and CLInf patients, although there was no evidence for decreased IL-7 or increased soluble IL7-Rα, both possible mechanisms for signaling defects in memory cells. However, effector cells that were present in Inf and CLInf patients had lower percentages of HLA-DR suggesting impaired function. These changes in T cell populations appear to reflect chronicity of infection, as filarial-infected children, despite the presence of active infection, did not show alterations in the frequencies of these T cell phenotypes. These data indicate that filarial-infected patients have contracted TCM compartments and a defect in effector cell development, defects that persist even following clearance of infection. The fact that these global changes in memory and effector cell compartments do not yet occur in infected children makes early treatment of LF even more crucial
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