1,221 research outputs found
Shape changing nonlocal molecular deformations in a nematic liquid crystal system
Abstract The nature of nonlinear molecular deformations in a homeotropically aligned nematic liquid crystal (NLC) is presented. We start from the basic dynamical equation for the director axis of a NLC with elastic deformation and mapped onto a integro-differential perturbed Nonlinear Schrodinger equation which includes the nonlocal term. By invoking the modified extended tangent hyperbolic function method aided with symbolic computation, we obtain a series of solitary wave solutions. Under the influence of the nonlocality induced by the reorientation nonlinearity due to fluctuations in the molecular orientation, the solitary wave exhibits shape changing property for different choices of parameters. This intriguing property as a result of the relation between the coherence of the solitary deformation and the nonlocality reveals a strong need for a deeper understanding in the theory of self-localization in NLC systems
Affinity study of -lactalbumin nanoparticles in a mixed solvent environment using Laplace transform technique
ABSTRACT. Effect of pH and cosolvent on the stabilization of protein structure is a well established study in protein or food science. Of the various interesting applications of protein nanoparticles, making it as a drug or bioactive compound carrier is of vital importance. This application of protein nanoparticle demands the affinity priority of protein with the available components of the medium. The basis of such studies lies in the synthesis of such protein nanoparticles and their characterizations. Secondly the knowledge of priority in affinity of protein to a particular solvent is essential. On this basis, the present work deals with the ultrasonic analysis of hydophobic interactions exhibited by the α-lactalbumin nanoparticle synthesised by heat treatment using acetone as desolvating agent. In order to enrich the variations in hydrophobicity, pH and cosolvent (fructose) are included in the study. The results are compared with one of our earlier work and are interpreted in terms of the interactions existing among the components and the evolved discussions reveal that the bulk nature of the medium is controlled by the existing hydrophobicity interactions. Further, as a novel attempt, the preference of protein particle to interact with a particular solvent in mixed solvent environment is elucidated using Laplace transform technique. This approach is expected to torch light in protein science in fixing the most desirable solvent in mixed solvent environment.
KEY WORDS: a-Lactalbumin, Fructose, Laplace Transform, Diffusion, Hydrophobic interactions
Bull. Chem. Soc. Ethiop. 2021, 35(3), 659-668.
DOI: https://dx.doi.org/10.4314/bcse.v35i3.1
Predictive Modelling for Medical Image Analysis Using Deep Learning Techniques
Recent advancements in healthcare for the prediction of autosomal diseases have led to the usage of deep learning algorithms in analysing medical images. Autosomal diseases are an extensive group of illnesses that range from cardiovascular diseases to specific types of tumours. Leveraging Convolutional Neural Networks (CNNs) and Recurrent Neural Networks (RNNs) can forecast models accurately and then very efficiently, but it has limitations in finding autosomal chromosomes. The autosomal chromosome uses advanced deep-learning algorithms to analyse a database of medical images, including MRI and CT scans, to predict the onset and progression of inherited disorders. Predictive accuracy is maximized by the usage of data preparation, model training, and learning strategies. The prognosis and early finding of autosomal diseases can be greatly enhanced by algorithms for timely intervention and customized treatment for patients. Further integration of analysing medical images can give more patient care and improve disease prediction results, particularly in the case of autosomal disorders and diagnosis
Magnetization reversal in a site-dependent anisotropic Heisenberg ferromagnet under electromagnetic wave propagation
Abstract Information density and switching of magnetization offers an interesting physical phenomenon which invoke magneto-optical techniques employed on the magnetic medium. In this paper, we explore the soliton assisted magnetization reversal in the nanosecond regime in the theoretical framework of the Landau–Lifshitz–Maxwell (LLM) model. Starting from the Landau–Lifshitz equation, we employ the reductive perturbation method to derive an inhomogeneous nonlinear Schrodinger equation, governing the nonlinear spin excitations of a site-dependent anisotropic ferromagnetic medium under the influence of electromagnetic (EM) field in the classical continuum limit. From the results, it is found that the soliton undergoes a flipping thereby indicating the occurrence of magnetization reversal behavior in the nanoscale regime due to the presence of inhomogeneity in the form of a linear function. Besides, the spin components of magnetization are also evolved as soliton spin excitations
Synergistic Effect between Carbon Dopant in Titania Lattice and Surface Carbonaceous Species for Enhancing the Visible Light Photocatalysis
Visible light-sensitive carbon doped titanium dioxide (C-TiO2) was prepared by grinding anatase TiO2 with anhydrous D-glucose solution as carbon source followed by calcination. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), BET surface area measurements, scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), FTIR analysis and photoluminescence (PL) techniques. The results confirmed the interstitial incorporation of carbon atoms in the TiO2 lattice via Osingle bondTisingle bondC and Tisingle bondOsingle bondC surface states. The calculation of valence band (VB) edge position of C-TiO2 by using electronegativity values shows cathodic shift with increase in the carbon concentration and this renders high oxidative power for photogenerated holes. The observed new electronic state above the VB edge was responsible for the electronic origin of band gap narrowing and visible light photoactivity of C-TiO2. The carbon atom was also present as carbonaceous species on the surface which acts as sensitizer. The photocatalytic activity of C-TiO2 was evaluated for the degradation of 4-chlorophenol under both UV and solar irradiation. The undoped TiO2 showed better activity under UV light whereas C-TiO2 showed higher photocatalytic activity under visible light. The pretreatment of C-TiO2 with UV light reduced the visible light activity due to the removal of surface carbonaceous species. The synergistic effect of surface carbonaceous species along with interstitial carbon is discussed in detail and accounted for visible light activity
Evaluation of chronic gastritis with Helicobacter pylori using updated Sydney system
Background: Helicobacter pylori has been established as a major etiological factor in the pathogenesis of chronic gastritis. The aim of the study was to interpret the histopathological changes in chronic gastritis using updated Sydney system and the association with H. pylori infection.Methods: This was a 3 years study in which 62 gastric endoscopic mucosal biopsies taken from patients presenting with dyspepsia were included. Slides were stained with routine H and E and Giemsa for H. pylori detection in chronic gastritis cases. Grading of the variables were done with reference to Sydney system of classification.Results: Out of 62 gastric biopsy specimens, 55 cases (88.7%) were histopathological diagnosed as chronic gastritis. Among chronic gastritis, 21 (38%) cases showed H. pylori and majority of these being moderately (2+) positive. 27 (49%) cases showed neutrophilic activity with most of them showed mild (1+) activity. Chronic inflammation was seen 52 (94.5%) with majority of these graded as moderate (2+). Intestinal metaplasia was seen in 8 (14.5%) of cases with majority being mild (1+). Atrophy was seen only in 3 (5.4%) of cases with majority being mild (1+). Significant statistical association was found between H. pylori and neutrophilic activity (p<0.001).Conclusions: Histological evaluation of chronic gastritis using updated Sydney system of classification helps in detection of H. pylori infection and prevents further progression of the disease.
Bulk and surface modification of TiO2 with sulfur and silver: Synergetic effects of dual surface modification in the enhancement of photocatalytic activity
Sulfur ion (S6+) was incorporated into the TiO2 lattice (Ti0.85S0.15O2) using sulfur powder as precursor. 0.05% of silver was deposited on the surface of Ti0.85S0.15O2 by photoinduced deposition method. The photocatalytic reactivity of TiO2, Ag-TiO2, Ti0.85S0.15O2 and Ag-Ti0.85S0.15O2 photocatalysts were probed for the degrdn. of a model compd. congo red (CR) dye under UV/solar light illumination. FTIR and XPS results suggested that the dopant sulfur ion (S6+) was incorporated into the TiO2 crystal lattice at Ti4+ lattice site and the sulfur ions on the surface were modified as SO42- active sites serving as electron withdrawing group. TEM and XPS anal. of Ag-Ti0.85S0.15O2 has confirmed the deposition of silver in the Ag0 state. Ag-Ti0.85S0.15O2 shows better photoactivty under solar light irradn. when compared to all the other photocatalysts. The enhanced photocatalytic activity of this catalyst is attributed to the synergetic effects of the incorporated dopant electronic energy level with the dual surface modifications of the type SO42- active centers and Schottky junctions created by metallic Ag0. Further the deposited Ag particles plays a dual role one as a sensitizer due to the Surface Plasmon Resonance (SPR) effect and also acts as an electron trapper under solar light illumination reducing the recombination of photogenerated charge carriers
Electrochemical synthesis and characterization of cubic magnetite nanoparticle in aqueous ferrous perchlorate medium
Abstract Electrochemical synthesis of cubic magnetite nanoparticle (MNP) in ferrous perchlorate aqueous medium and its spectral investigations have been carried out. The structural property of MNP is evidenced by X-ray diffraction pattern shows the characteristic peaks. Further the vibrational frequencies of MNP are evaluated using FT-IR and Raman spectroscopic techniques. UV–visible spectroscopic studies show the possibility of surface plasmon resonance effect. The cubic structure of MNP has been confirmed by transmission electron microscope (TEM) technique and it is also evidenced by scanning electron microscope (SEM). The as-synthesized MNP shows superparamagnetic property which is confirmed by the vibrating sample magnetometer, hence it could be useful for synthesis of very ultra superparamagnetic iron oxide solution (VUSPIO) for cancer treatment
SEAD Virtual Archive: Building a Federation of Institutional Repositories for Long Term Data Preservation
Major research universities are grappling with their response to the deluge of scientific data emerging through research by their faculty. Many are looking to their libraries and the institutional repository as a solution. Scientific data introduces substantial challenges that the document-based institutional repository may not be suited to deal with. The Sustainable Environment - Actionable Data (SEAD) Virtual Archive specifically addresses the challenges of “long tail” scientific data. In this paper, we propose requirements, policy and architecture to support not only the preservation of scientific data today using institutional repositories, but also its rich access and use into the future
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Relationship Between Foveal Cone Structure and Visual Acuity Measured With Adaptive Optics Scanning Laser Ophthalmoscopy in Retinal Degeneration.
PurposeTo evaluate foveal function in patients with inherited retinal degenerations (IRD) by measuring visual acuity (VA) after correction of higher-order aberrations.MethodsAdaptive optics scanning laser ophthalmoscopy (AOSLO) was used to image cones in 4 healthy subjects and 15 patients with IRD. The 840-nm scanning laser delivered an "E" optotype to measure AOSLO-mediated VA (AOSLO-VA). Cone spacing was measured at the preferred retinal locus by two independent graders and the percentage of cones below the average density of 47 age-similar healthy subjects was computed. Cone spacing was correlated with best-corrected VA measured with the Early Treatment of Diabetic Retinopathy Study protocol (ETDRS-VA), AOSLO-VA, and foveal sensitivity.ResultsETDRS-VA significantly correlated with AOSLO-VA (ρ = 0.79, 95% confidence interval [CI] 0.5-0.9). Cone spacing correlated with AOSLO-VA (ρ = 0.54, 95% CI 0.02-0.7), and negatively correlated with ETDRS letters read (ρ = -0.64, 95% CI -0.8 to -0.2). AOSLO-VA remained ≥20/20 until cones decreased to 40.2% (CI 31.1-45.5) below normal. Similarly, ETDRS-VA remained ≥20/20 until cones were 42.0% (95% CI 36.5-46.1) below normal. Cone spacing z scores negatively correlated with foveal sensitivity (ρ = -0.79, 95% CI -0.9 to -0.4) and foveal sensitivity was ≥35 dB until cones were 43.1% (95% CI 39.3-46.6) below average.ConclusionsVA and foveal cone spacing were weakly correlated until cones were reduced by 40% to 43% below normal. The relationship suggests that VA is an insensitive measure of foveal cone survival; cone spacing may be a more sensitive measure of cone loss
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