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Serum biomarkers identification by iTRAQ and verification by MRM: S100A8/S100A9 levels predict tumor-stroma involvement and prognosis in Glioblastoma
No full textDespite advances in biology and treatment modalities, the prognosis of glioblastoma (GBM) remains poor. Serum reflects disease macroenvironment and thus provides a less invasive means to diagnose and monitor a diseased condition. By employing 4-plex iTRAQ methodology, we identified 40 proteins with differential abundance in GBM sera. The high abundance of serum S100A8/S100A9 was verified by multiple reaction monitoring (MRM). ELISA and MRM-based quantitation showed a significant positive correlation. Further, an integrated investigation using stromal, tumor purity and cell type scores demonstrated an enrichment of myeloid cell lineage in the GBM tumor microenvironment. Transcript levels of S100A8/S100A9 were found to be independent poor prognostic indicators in GBM. Medium levels of pre-operative and three-month post-operative follow-up serum S100A8 levels predicted poor prognosis in GBM patients who lived beyond median survival. In vitro experiments showed that recombinant S100A8/S100A9 proteins promoted integrin signalling dependent glioma cell migration and invasion up to a threshold level of concentrations. Thus, we have discovered GBM serum marker by iTRAQ and verified by MRM. We also demonstrate interplay between tumor micro and macroenvironment and identified S100A8 as a potential marker with diagnostic and prognostic value in GBM. © 2019, The Author(s)
Hydrodynamic moraine-breach modeling and outburst flood routing - A hazard assessment of the South Lhonak lake, Sikkim
No full textThe presence of glacial lakes in the Himalaya makes it a potential mountain hazard, as catastrophic failure of such waterbodies may lead to high-magnitude glacial lake outburst flood (GLOF) events that can cause significant damage to the low-lying areas. The present study evaluates the hazard potential of the South Lhonak lake located in the state of Sikkim, using both one and two-dimensional hydrodynamic modeling approaches. Different breach parameters were calculated based on the lake bathymetry and moraine dimensions. The worst-case GLOF scenario is revealed during an overtopping failure of the moraine, producing a peak flood of 6064.6 m 3 s �1 and releasing a total water volume of 25.7 � 10 6 m 3 . The GLOF hydrograph is routed to calculate peak flood (m 3 s �1 ), inundation depth (m) and flow velocity (ms �1 ) along the main flow channel. The interaction of the flood wave with a major topographic obstruction located 15.6 km downstream of the lake, shows a significant reduction of the flow energy leading to a minimization of the South Lhonak GLOF impact. The flood wave reaches the nearest town Lachen, located at a distance of 46 km downstream from the lake, at 3 h 38 min after the initiation of the breach, with a peak flood of 3928.16 m 3 s �1 and a maximum flow velocity of 13.6 ms �1 . At Chungthang town, located at a distance of 62.35 km from South Lhonak lake, the flood wave potentially inundates settlements along the bank of the flow channel, where a peak flood of 3828.08 m 3 s �1 is reached after 4 h of the initial dam breach event. The study also incorporates modeling of a framework to propose a potential flood remediation measure of the South Lhonak lake GLOF by demonstrating the effect of a lateral inline structure along the flow channel, to check the flow of the potential flood wave. © 2019 Elsevier B.V
27 Al MAS NMR investigations on Al 23 Te 77 glass: Observation of 5- coordinated Al and its influence on electrical switching
No full text27 Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) spectroscopic studies show that Al resides in 4-, 5- and 6- fold coordination in bulk Al 23 Te 77 glass. Also, Al 23 Te 77 glass is found to exhibit threshold type switching. Earlier studies report memory type switching in Al-Te glasses wherein Al has been found only in 4 Al and 6 Al environments. X-Ray Photo Electron Spectroscopic (XPS) measurements show the presence of Al 2 O 3 in Al 23 Te 77 glass network. The structural network of Al-Te glass has been cross linked by the presence of higher coordinated Al atoms. The structural reorganization becomes difficult due to the increased network connectivity. Thus, the memory switching (which requires an easy structural reorganization) is retarded, resulting in the observation of threshold switching. © 201
Cessation of a dense granular flow down an inclined plane
No full textThe cessation of a dense granular flow down an inclined plane upon decrease in the angle of inclination is studied using particle-based simulations for the linear and Hertzian particle contact models for ordered and disordered flows. The nature of the flow is examined by progressively decreasing the angle of inclination by fractions of a degree, with the objective of examining the range of angles for which the hard-particle model can be used to describe the flow and the nature of the flow dynamics very close to cessation where the hard-particle approximation fails. For a disordered flow, when the angle inclination exceeds the angle for flow cessation by about 0.5° for the linear contact model and about 1° for the Hertzian model, the flow is well described by Bagnold rheology, and the Bagnold coefficients are independent of layer height and the particle stiffness, implying that the flow dynamics is well described by the hard-particle approximation. When the angle of inclination exceeds the angle for flow cessation by less than 0.5° for the linear contact model and 1° for the Hertzian contact model, the flow transitions into a layered state consisting of a faster shearing zone of height about 30 particle diameters atop a bottom slowly shearing zone. There are sinusoidal oscillations in the velocity of the center of mass of the flow, and the period of these oscillations is proportional to the characteristic time for particle interactions, indicating that the particle contact time does affect the dynamics of the layered flow. The flow evolution is qualitatively different for an ordered flow. In this case, there is an abrupt transition from a Bagnold flow to a plug flow with sliding at the base when the angle of inclination is decreased by 0.05°. There is no discernible intermediate flow regime where the particle contact time becomes relevant. We also examine the deceleration of the flow when the angle of inclination is decreased from a flowing state to a final angle below the cessation angle. The initial decrease in the flow velocity is exponential for both contact models and for all final angles of inclination. This is followed by a more rapid decrease to the static state. The time constant for the initial decrease is significantly higher for an ordered flow in comparison to a disordered flow. The time constant is independent of the contact model and particle stiffness, and increases with height proportional to h3/2, as expected for the hard-particle model. © 2019 American Physical Society
Conformity and stability analysis of a modified spring-mass-damper system dynamics-based car-following model
No full textModeling the dynamics of a traffic system involves using the principles of both physical and social sciences since it is composed of vehicles as well as drivers. A novel car-following model is proposed in this paper by incorporating the socio-psychological aspects of drivers into the dynamics of a purely physics-based spring-mass-damper mechanical system to represent the driver-vehicle longitudinal movements in a traffic stream. The crux of this model is that a traffic system can be viewed as various masses interacting with each other by means of springs and dampers attached between them. While the spring and damping constants represent the driver behavioral parameters, the mass component represents the vehicle characteristics. The proposed model when tested for its ability to capture the traffic system dynamics both at micro, driver, and macro, stream, levels behaved pragmatically. The stability analysis carried out using perturbation method also revealed that the proposed model is both locally and asymptotically stable. © 2019 World Scientific Publishing Company
Universal evaporation dynamics of ordered arrays of sessile droplets
No full textManipulation of an array of surface droplets organised in an ordered structure turns out to be of immense consequence in a wide variety of applications ranging from photonics, near field imaging and inkjet printing on the one hand to bio-molecular analysis and DNA sequencing on the other. While evaporation of a single isolated sessile droplet has been well studied, the collective evaporative dynamics of an ordered array of droplets on a solid substrate remains elusive. Physically, the closed region between the centre and side droplets in the ordered array reduces the mobility of the diffusing vapour, resulting in its accumulation along with enhanced local concentration and a consequent increment in the lifetime of the centre droplet. Here, we present a theoretical model to account for evaporation lifetime scaling in closely placed ordered linear droplet arrays. In addition, the present theory predicts the limiting cases of droplet interaction; namely, critical droplet separation for which interfacial interaction ceases to exist and minimum possible droplet separation (droplets on the verge of coalescence) for which the droplet system achieves maximum lifetime scaling. Further experimental evidence demonstrates the applicability of the present scaling theory to extended dimensions of the droplet array, generalising our physical conjecture. It is also worth noting that the theoretical time scale is applicable across a wide variety of drop-substrate combinations and initial droplet volumes. We also highlight that the scaling law proposed here can be extended seamlessly to other forms of confinement such as an evaporating droplet inside a mini-channel, as encountered in countless applications ranging from biomedical engineering to surface patterning. © 2019 Cambridge University Press
Atomically locked interfaces of metal (Aluminum) and polymer (Polypropylene) using mechanical friction
No full textJoining different parts is one of the crucial components of designing/engineering of materials. Presently, the current energy efficient low weight automotive and aerospace components consist of a different class of materials, such as metals, polymers, ceramics, etc. Joining these components remains a challenge. Here, we demonstrate metal (aluminum) and polymer (Polypropylene, pp) joining using mechanical friction. The detailed characterization clearly demonstrates that atomically locked interfaces are formed in such joining and no chemical bonds are formed during the joining. Also, a waterproof and strong interface is formed in such a process. Fully atomistic molecular dynamics simulations were also carried out in order to further gain insights on the joining process. © 2019 Elsevier Lt
2D Linear Detector Based on Generalized Belief Propagation Algorithm
No full textVarious ideas have been borrowed from 1D inter symbol interference (ISI) detectors towards approximation of near maximum likelihood (ML) detection over 2D ISI channels. Generalized belief propagation (GBP) algorithm is a graph based algorithm different from these algorithms and is observed to give the best bit error rate (BER) performance by minimizing KL-distance metric. GBP algorithm passes messages between regions instead of messages between nodes in an iterative fashion. However, GBP algorithm has a very high computational complexity and is not suitable for practical deployment. In this paper, we propose a GBP based signal detection algorithm using a quadratic approximation of the KL-distance metric. This allows us to minimize the cost function by solving a set of linear equations i.e., obtain a one shot solution instead of the iterative message passing in the GBP algorithm. We also provide an intuition into the nature of the hard decisions given by the algorithm. The idea opens up various approximations of the GBP algorithm using different convex approximations of the cost function with the desired nature of obtaining the solution. We show the efficacy of the proposed algorithm by detecting 5�5 pages of binary data over a chosen channel with 3�3 ISI span. The quadratic approximation is observed to give 1.5 dB inferior performance in signal-to-noise ratio (SNR) as compared to the GBP algorithm. © 2018 IEEE
Storm characteristics and precipitation estimates of monsoonal clouds using C-band polarimetric radar over Northwest India
No full textStorm is a convective cell much smaller than a mesoscale convective system (MCS) but typically larger than a cumulonimbus cloud and heavy precipitation and lightning are often associated with it. Storms contribute major fraction of the convective precipitation in MCSs. Storm characteristics and precipitation estimates around New Delhi (28.6°N, 77.2°E; an Indian land location) during June�September period of the year 2013 are reported here using data of C-band polarimetric Doppler weather radar. Storms, defined based on radar reflectivity thresholds (30 dBZ for simple storms and 40 dBZ for intense storms), are tracked and their properties are extracted. Our results show that about 80 of storms exist for 1 h or less. The areas of 90 of simple storms are less than 100 km 2 and the largest area averaged over storm lifespan does not exceed 400 km 2 . The majority of storms (> 80) move with speeds less than 30 km h �1 . About 60�65 of simple/intense storms have echo top heights between 6 and 10 km, while only few of them exceed 17 km. The values of average thickness of simple and intense storms lie between ~ 2�10 and ~ 1�7 km, respectively. It is not the vertical extent of a storm but its area-time integral that correlates better with the total precipitation amount. Around the New Delhi area, daily accumulated precipitation derived from relations incorporating polarimetric variables is in good agreement with the rain gauge measurements while that obtained from relations based on radar reflectivity factor (Z h ) alone highly underestimates precipitation. This suggests that polarimetric capability is needed in Doppler weather radars to get the realistic precipitation estimates. The mean precipitation water content derived from Z h (~ 0.96 g m �3 ) is about 30�40 less compared to that derived from polarimetric relations. Our findings on storm properties have implications for cloud parameterizations and in short-term weather forecasting. © 2019, Springer-Verlag GmbH Austria, part of Springer Nature
Photon-Free Degradation of Dyes by Ge/GeO 2 Porous Microstructures
No full textSeveral industries use dyes as coloring agents and release untreated effluents in the form of wastewater that has created panic due to the environmental issue. Considerable efforts have been extended to develop photocatalysts for the degradation of these dyes. Here, we report the photon-free degradation of various cationic and anionic dyes for the first time by Ge/GeO 2 porous microstructures. The degradation efficiency and time are found to be dependent on the catalyst amount, and it is possible to achieve �100 degradation without any external stimuli. Our experimental results indicate that Ge donates electrons either directly to dye molecules or to dissolved oxygen (O 2 ) molecules and creates superoxide species without any extra energy source that bleaches or degrades the dyes. However, it is essential to have a continuous supply of electrons from Ge core to sustain the degradation process. © Copyright 2019 American Chemical Society