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Exploring the potential of newly synthesized 4-methyl-6-morpholino-pyrimidine derivatives as antiproliferative agents
No full textIn view of exploring the potential of pyrimidine derivatives as anticancer agents, a series of 4-methyl-6-morpholinopyrimidine derivatives was synthesised and characterised by NMR (H-1 & C-13), SC-XRD and mass spectral analysis. The in vitro anticancer activity of these compounds was investigated using different human cancer cell lines, namely HeLa (cervix), NCI-H460 (lung), MCF-7 (breast), HepG2 (liver) and IMR-32 (brain). Compounds 4c and 5h exhibited potent anticancer activity in a dose-dependent manner as compared to other derivatives, with IC50 values of 5.88 +/- 1.22 and 6.11 +/- 2.12 mu M on HeLa and NCI-H460, cells respectively. The inhibitory effect of 4c and 5h on cancer cell proliferation was shown to be a consequence of reactive oxygen species (ROS) generation and subsequent induction of cellular apoptosis, as evidenced by an increase in hypodiploid (subG1) population, early apoptotic cell population, caspase-3/7 activity, loss of mitochondrial membrane potential and degradation of nuclear DNA. Furthermore, molecular docking studies revealed that 4c and 5h compounds bind to the ATP binding pocket of the mammalian target of rapamycin (mTOR). Based on our results, we conclude that 4-methyl-6-morpholinopyrimidine derivatives prevent cancer cell proliferation by inducing apoptosis and thus have potential to be further explored for anticancer properties
Signal Processing and Coding Techniques for 2-D Magnetic Recording: An Overview
No full textTwo-dimensional magnetic recording (TDMR) is an emerging storage technology that aims to achieve areal densities on the order of 10 Tb/in 2, mainly driven by innovative channels engineering with minimal changes to existing head/ media designs within a systems framework. Significant additive areal density gains can be achieved by using TDMR over bit patterned media (BPM) and energy-assisted magnetic recording (EAMR). In TDMR, the sectors are inherently 2-D with reduced track pitch and bit widths, leading to severe 2-D intersymbol interference (ISI). This necessitates the development of powerful 2-D signal processing and coding algorithms for mitigating 2-D ISI, timing artifacts, jitter, and electronics noise resulting from irregular media grain positions and read-head electronics. The algorithms have to be eventually realized within a read/write channel architecture as a part of a system-on-chip (SoC) within the disk controller system. In this work, we provide a wide overview of TDMR technology, channel models and capacity, signal processing algorithms (detection and timing recovery), and error-correcting codes attuned to 2-D channels. The innovations and advances described not only make TDMR a promising future technology, but may serve a broader engineering audience as well
Image based shape characterization of granular materials and its effect on kinematics of particle motion
No full textQuantification of particle shape features to characterize granular materials remains an open problem till date, owing to the complexity involved in obtaining the geometrical parameters necessary to adequately compute the shape components (sphericity, roundness and roughness). A new computational method based on image analysis and filter techniques is proposed in this paper to overcome this difficulty. In this method, operations are performed on binary images of particles obtained from raster images (collection of pixels) by the process of image segmentation. The boundary of particles captured in 2D images consist of micro, meso and macro scale features on which filter techniques are applied to remove the micro level features for the quantification of particle roughness and to obtain a roughness free boundary. A robust algorithm is then written and implemented in MATLAB to obtain the complete geometry of the particle boundary (free from roughness features) and to identify the precise corner and non-corner regions along the boundary. This information is used to quantify the roundness (as per Wadell in J Geol 40:443-451, 1932) and sphericity of particles. The proposed methodology to measure roundness and sphericity is compared against standard visual charts provided by earlier researchers. Finally, the methodology is demonstrated on real soil particles falling across a wide range of sizes, shapes and mineralogical compositions. Also, an idea to comprehend the kinematics of particle motion based on its concavo-convex features is discussed with two proposed novel descriptors and a visual classification chart
Alkali metal ion co-doped Eu3+ activated GdPO4 phosphors: Structure and photoluminescence properties
No full textSeries of alkali metal ion co-doped with Eu3+ activated GdPO4 phosphors were synthesized by the conventional solid state method. Structural parameters were confirmed by the X-ray Rietveld refinement method. All the compounds are crystallized in the monazite phase with space group (P12(1)/n(1), No.14). Morphology and functional group analysis were performed on scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Room temperature photoluminescence (PL) spectroscopic results reveal that, on Eu3+ ion doping in the GdPO4 host matrix, the magnetic dipole transition (D-5(0) -> F-7(1)) at 581 nm responsible for orange light, dominates the red emission with respect to the electric dipole transition (D-5(0) -> F-7(2)) at 620 nm. It was found that the emission intensity increased up to 9 mol% of Eu3+ and then quenched due to multipolar interactions. Further, co-doping with Li+, Na+ and K+ ion in to Eu3+ activated GdPO4 phosphor led to an enhancement in luminescence intensity by reducing the parity restriction of electric dipole transitions as a consequence of suitable local distortion of the crystal field surrounding the Eu3+ activator ion. The results of Judd-Ofelt theory and radiative parameters suggest that these phosphors have a short lifetime, good quantum efficiency, excellent color purity compared to other reported Eu3+ doped phosphors. These results illustrate the mechanistic effect of alkali metal ions doping on luminescent properties of rare earth ion doped GdPO4 phosphors and help in optimization of their luminescent properties according to the practical requirements in optoelectronic and biomedical applications. (C) 2018 Elsevier B.V. All rights reserved
UFCN: a fully convolutional neural network for road extraction in RGB imagery acquired by remote sensing from an unmanned aerial vehicle
No full textRoad extraction in imagery acquired by low altitude remote sensing (LARS) carried out using an unmanned aerial vehicle (UAV) is presented. LARS is carried out using a fixed wing UAV with a high spatial resolution vision spectrum (RGB) camera as the payload. Deep learning techniques, particularly fully convolutional network (FCN), are adopted to extract roads by dense semantic segmentation. The proposed model, UFCN (U-shaped FCN) is an FCN architecture, which is comprised of a stack of convolutions followed by corresponding stack of mirrored deconvolutions with the usage of skip connections in between for preserving the local information. The limited dataset (76 images and their ground truths) is subjected to real-time data augmentation during training phase to increase the size effectively. Classification performance is evaluated using precision, recall, accuracy, F1 score, and brier score parameters. The performance is compared with support vector machine (SVM) classifier, a one-dimensional convolutional neural network (1D-CNN) model, and a standard two-dimensional CNN (2D-CNN). The UFCN model outperforms the SVM, 1D-CNN, and 2D-CNN models across all the performance parameters. Further, the prediction time of the proposed UFCN model is comparable with SVM, 1D-CNN, and 2D-CNN models. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE
The Power of Side-Information in Subgraph Detection
No full textIn this paper, we tackle the problem of hidden community detection. We consider belief propagation (BP) applied to the problem of detecting a hidden Erdos-Renyi (ER) graph embedded in a larger and sparser ER graph, in the presence of side-information. We derive two related algorithms based on BP to perform subgraph detection in the presence of two kinds of side-information. The first variant of side-information consists of a set of nodes, called cues, known to be from the subgraph. The second variant of side-information consists of a set of nodes that are cues with a given probability. It was shown in past works that BP without side-information fails to detect the subgraph correctly when a so-called effective signal-to-noise ratio parameter falls below a threshold. In contrast, in the presence of nontrivial side-information, we show that the BP algorithm achieves asymptotically zero error for any value of a suitably defined phase-transition parameter. We validate our results on synthetic datasets and a few real world networks
Germanane MOSFET for Subdeca Nanometer High-Performance Technology Nodes
No full textBallistic transport in monolayer Germanane MOSFETs is investigated for high-performance (HP) applications. Characteristics of both n- and p-type transistors having channel lengths of 7, 5, and 3 nm are studied and compared against the International Technology Roadmap for Semiconductor (ITRS) target of 2028. Our simulation approach is based on a self-consistent quantum ballistic transportmodel within the framework of the nonequilibrium Green's function formalism and relies on a single-band and a two-band k.p Hamiltonian for n- and p-type channels, respectively. We found that, even for a gate length scaled down to 3 nm, the ON current (I-ON) in n- and p-MOSFETs for a fixed OFF current I-OFF = 100 nA/mu m is as high as similar to 890 and 700 mu A/mu m, respectively. For longer channel lengths, the p-MOSFET can outperform the n-MOSFET in terms of I-ON requirements, as the direct source-to-drain tunneling gets suppressed. Other performance metrics, including gate capacitance, intrinsic switching delay, and switching energy, have also been calculated and found to be comparable to the ITRS 2028 HP technology requirements
Aridification driven diversification of fan-throated lizards from the Indian subcontinent
No full textThe establishment of monsoon climate and the consequent aridification has been one of the most important climate change episodes in the Indian subcontinent. However, little is known about how these events might have shaped the diversification patterns among the widely distributed taxa. Fan-throated lizards (FTL) (Genus: Sitana, Sarada) are widespread, diurnal and restricted to the semi-arid zones of the Indian subcontinent. We sampled FTL in 107 localities across its range. We used molecular species delimitation method and delineated 15 species including six putative species. Thirteen of them were distinguishable based on morphology but two sister species were indistinguishable and have minor overlaps in distribution. Five fossils were used to calibrate and date the phylogeny. Diversification of fan-throated lizards lineage started similar to 18 mya and higher lineage diversification was observed after 11 my. The initial diversification corresponds to the time when monsoon climate was established and the latter was a period of intensification of monsoon and initiation of aridification. Thirteen out of the fifteen FTL species delimited are from Peninsular India; this is probably due to the landscape heterogeneity in this region. The species poor sister genus Otocryptis is paraphyletic and probably represents relict lineages which are now confined to forested areas. Thus, the seasonality led changes in habitat, from forests to open habitats appear to have driven diversification of fan-throated lizards
Temporal change and flow velocity estimation of Patseo glacier, Western Himalaya, India
No full textIn the present study we estimate the velocity and thickness of the Patseo glacier, Himachal Pradesh, India. The average velocity of the glacier was estimated as similar to 5.47 m/year using co-registration of optically sensed images and correlation (COSI-Corr) method. The glacier thickness was found to vary between 12 and 278 m, with an average value 59 m. The total glacier ice volume was estimated as similar to 15.8 x 10(7) m(3), with equivalent water reservoir of similar to 14.5 x 10(7) m(3). Ground penetrating radar (GPR) surveys were conducted during 2004 and 2013 for validation of the estimated glacier thickness. The glacier thickness estimated using COSI-Corr method was found to be in agreement with GPR-retrieved glacier thickness (RMSE = 4.75 m; MAE = 3.74 m). The GPR profiles collected along the same geographic locations on the glacier during 2004 and 2013 showed a reduction in ice thickness of similar to 1.89 m, and thus resulting in an annual ice thickness decrease of similar to 0.21 m. The glacier area was estimated for 2004 and 2013 using LISS IV satellite data and found to be similar to 2.52 and similar to 2.30 sq. km respectively. This shows an annual reduction of similar to 0.024 sq. km in glacier area. The total annual loss in glacier ice volume was estimated as similar to 4.55 x 10(5) m(3). This loss in the glacier ice volume of the Patseo glacier is supported by the snow and meteorological observations collected at a nearby field observatory of Snow and Avalanche Study Establishment (SASE). The climate data collected at SASE meteorological observatory at Patseo (3800 m), between 1993-94 and 2014-15 showed an increasing trend in the mean annual temperature and a decreasing trend in winter precipitation
Reduction Responsive Nanovesicles Derived from Novel alpha-Tocopheryl-Lipoic Acid Conjugates for Efficacious Drug Delivery to Sensitive and Drug Resistant Cancer Cells
No full textTwo novel a-tocopheryl-lipoic acid conjugates (TL1 and TL2) were synthesized for the anticancer drug, doxorubicin (DOX), delivery. Both conjugates were able to form stable nanovesicles. The critical aggregation concentration (CAC) was determined using 4-(N,N-dimethylamino)cinnamaldehyde. (DMACA) as a fluorescence probe. Formation of highly packed nanovesicles was characterized by 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence anisotropy and micro viscosity measurements. The morphologies of nanovesicles were visualized by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The response of nanovesicles to reducing environment of cells was probed by the addition of dithiothreitol (DTT), which was followed by the increase in the hydrodynamic diameter under dynamic light scattering (DLS) measurements. The encapsulation efficiency of a commonly used anticancer drug, doxorubicin (DOX), in nanovesicles was found to be similar to 60% and, similar to 55% for TL1 and TL2, respectively (TL1-DOX and TL2-DOX). Also, the cumulative drug (DOX) release from DOX-encapsulated nanovesicles in response to biological reducing agent glutathione (GSH) was similar to 50% and similar to 40% for TL1-DOX and TL2-DOX, respectively, over a period of 10 h. Both TL1-DOX and TL2-DOX delivered the anticancer drug, doxorubicin (DOX), across the DOX-sensitive and DOX-resistant HeLa (HeLa-DOXR) cells in an efficient manner and significantly more efficaciously than the drug alone treatments, especially in HeLa-DOXR cells. The nanovesicle mediated DOX treatment also showed significantly higher cell death when compared to DOX alone treatment in HeLa-DOXR cells. Blood compatibility of the nanovesicles was supported from clotting time, hemolysis, and red blood cell (RBC) aggregation experiments for their potential'in vivo applications. Concisely, we present biocompatible and responsive nanovesicles for efficacious drug delivery to drug-sensitive and drug-resistant cancer cells