Delhi Technological University

About: Delhi Technological University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 4427 authors who have published 6761 publications receiving 71035 citations. The organization is also known as: Delhi College of Engineering & DTU.

IL-2 mediates NK cell proliferation but not hyperactivity

Abstract: Natural killer cells play a major role in innate immunity against tumor and virus-infected cells. NK cells express activating and inhibitory receptors to regulate their function. It has been established that modulation in the NK cell receptor profile results in altered function of NK cell against target cells. Here, we study the effect of IL-2 stimulation on NK cell inhibitory receptors Ly49A, Ly49C, and activating receptor Ly49D in C57BL/6 mice. It was observed that there was significant increase in expression of Ly49A but no change in expression of Ly49C and Ly49D on IL-2 stimulation. We further noticed that although IL-2 stimulation increased the NK cell population and expression of activation marker NK1.1 but IL-2 stimulation does not cause hyper-responsiveness in NK cells, as there was no increase in MIP-1α and IFN-γ production in IL-2 stimulated NK cells as compared to unstimulated controls. These findings provide a framework to understand the effect of IL-2 stimulation on cognate and non-cognate receptor ligand interactions and suggest stratagies for immunotherapies in conjunction with IL-2 combinatorial therapies.

Design and modelling of dispersion-engineered rib waveguide for ultra broadband mid-infrared supercontinuum generation

Abstract: We report a dispersion-engineered As2Se3 chalcogenide glass rib waveguide structure for ultra broadband mid-infrared supercontinuum generation across molecular ‘fingerprint region’. The proposed rib waveguide structure offers non-linear coefficient as high as 18,250 W−1 km−1 at 2.5 μm. Supercontinuum spectrum spanning 2–15 μm, which not only covers the both atmospheric transparent windows (3–5 μm and 8–13 μm) in the mid-infrared domain but also covers the important molecular ‘fingerprint domain’, is obtained using only 4 mm-long rib waveguide structure. To the best of our knowledge, such broadband mid-infrared supercontinuum spectrum in As2Se3-based chalcogenide waveguide geometry is reported for the first time. The proposed design of rib waveguide has potential for robust, integrated and low-cost supercontinuum sources in various applications including frequency comb generation, chemical sensing, food quality control and early cancer diagnostics.

A study on brain tumor segmentation using convolution neural network

Abstract: Computer vision is playing important role in the field of human health care. This role is growing day by day. The application of computer vision techniques in health care has one of the aim to reduce human judgement in diagnosis. Thus, human error in judgement may be reduced. Brain related diagnosis demands at most care and a minute error in judgment may be disastrous. This makes medical imaging very important field. Various imaging methods like CT Scans, X-Ray, and MRI are available but MRI is the most reliable and safe. Even the smallest aberrances in the human body can be identified using imaging techniques. More preferred contrast information about brain tissues is provided by Magnetic Resonance imaging (MRI). Image segmentation is an important problem in medical imaging, which involves separating the tumor and organisms out of the medical data. Machine learning (ML) has gained enormous application with innovation in hardware requirements for computing. Convolutional neural networks (CNN) is one of the most effective techniques in ML. CNN has find applications in almost every field of research. CNN also find effective applications in brain MRI segmentation. In this paper, we present a study on CNN based MRI segmentation.

Near UV based Dy3+ ions doped alkaline-earth chloro borate glasses for white LED’s and visible lasers

Abstract: A new series of Dy3+ ions doped alkaline-earth chloro borate (AECB) glasses were prepared by conventional melt quenching technique and characterized with XRD, absorption, excitation, photoluminescence (PL), fluorescence decay spectral measurements and CIE coordinates. From the absorption spectra, Judd-Ofelt (J-O) intensity parameters (Ω2, Ω4, Ω6) have been measured using the least square fit method. Under 385 nm excitation, intense blue, yellow emissions at 483 and 576 nm and weak red emission at 665 nm were observed, which are assigned to the 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 and 4F9/2 → 6H11/2 transitions of Dy3+ respectively. The yellow-to-blue emission intensity ratios and CIE chromaticity coordinates have been determined from emission spectra to evaluate the emitted light as a function of Dy3+ concentration. The CIE chromaticity coordinates of Dy3+ (1 mol%) doped AECB glasses are located in the white light region. The optimum doping concentration of Dy3+ ions is around 1 mol%, beyond which concentration quenching is observed. The decay spectral profiles of 4F9/2 → 6H13/2 (577 nm) luminescence transition were used to measure experimental lifetimes (τR). The results indicate that Dy3+ doped AECB glasses may have great potential as a single-component white-light-emitting glass for UV-light-emitting diodes and for other visible photonic applications.