38 research outputs found

    Test and characterization of a prototype silicon-tungsten electromagnetic calorimeter

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    New generation high-energy physics experiments demand high precision tracking and accurate measurements of a large number of particles produced in the collisions of lementary particles and heavy-ions. Silicon-tungsten (Si-W) calorimeters provide the most viable technological option to meet the requirements of particle detection in high multiplicity environments. We report a novel Si-W calorimeter design, which is optimized for γ/π0\gamma/\pi^0 discrimination up to high momenta. In order to test the feasibility of the calorimeter, a prototype mini-tower was constructed using silicon pad detector arrays and tungsten layers. The performance of the mini-tower was tested using pion and electron beams at the CERN Proton Synchrotron (PS). The experimental results are compared with the results from a detailed GEANT-4 simulation. A linear relationship between the observed energy deposition and simulated response of the mini-tower has been obtained, in line with our expectations.Comment: 13 figures, represents test beam data with PS beam line at CER

    Evaluation of Cyclosaplin Efficacy Using a Silk Based 3D Tumor Model

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    Development of novel anti-cancer peptides requires a rapid screening process which can be accelerated by using appropriate in vitro tumor models. Breast carcinoma tissue is a three-dimensional (3D) microenvironment, which contains a hypoxic center surrounded by dense proliferative tissue. Biochemical clues provided by such a 3D cell mass cannot be recapitulated in conventional 2D culture systems. In this experiment, we evaluate the efficacy of the sandalwood peptide, cyclosaplin, on an established in vitro 3D silk breast cancer model using the invasive MDA-MB-231 cell line. The anti-proliferative effect of the peptide on the 3D silk tumor model is monitored by alamarBlue assay, with conventional 2D culture as control. The proliferation rate, glucose consumed, lactate dehydrogenase (LDH), and matrix metalloproteinase 9 (MMP-9) activity of human breast cancer cells are higher in 3D constructs compared to 2D. A higher concentration of drug is required to achieve 50% cell death in 3D culture than in 2D culture. The cyclosaplin treated MDA-MB-231 cells showed a significant decrease in MMP-9 activity in 3D constructs. Microscopic analysis revealed the formation of cell clusters evenly distributed in the scaffolds. The drug treated cells were less in number, smaller and showed unusual morphology. Overall, these findings indicate the role of cyclosaplin as a promising anti-cancer therapeutic

    Late Quaternary sediments from Barakar-Damodar Basin, Eastern India include the 74 ka Toba ash and a 17 ka microlith toolkit

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    The Youngest Toba Tuff (YTT, 74 ka ago) is considered as the product of one of the largest super-volcanic events in the Quaternary period, which possibly caused a disastrous effect on the climate and hominid habitation. Here, we report a rare occurrence of an ∼ 2 cm YTT ash bed in the Barakar-Damodar Late Quaternary sediments, Eastern India, and the Microlith toolkits that were found in the sedimentary deposits above the ash layer. The high silica content of the glass shards with bubble walls, blocky, rod-shaped structures, and pumice morphology, are similar to other YTT ash deposits. The sedimentary facies associated with the ash layer show a transition from lacustrine to fluvial depositional environments. Sedimentological, petrographical, mineralogical, geochemical, and magnetic properties suggest the ash was deposited in a lacustrine environment. Moreover, the discovery of the ash bed, the occurrence of in-situ Bovid species, and microlith assemblages in the Barakar-Damodar Valley add to our understanding of late Pleistocene depositional environments, hominin occupations, and possible local migration across eastern India during the Last Glacial Maximum (LGM) period

    Development and characterization of a large area silicon pad array for an electromagnetic calorimeter

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    We present the research and development work of the first version of a 6×6 array of silicon pad detectors, carried out in India, for the proposed forward calorimeter (FOCAL) as part of the ALICE collaboration upgrade program at CERN. The primary motivation is to develop a large area silicon pad array realizing the challenging requirements of high-energy physics experiments such as low leakage current, high breakdown voltage and evaluate its performance as an active layer in the prototype silicon tungsten (Si-W) electromagnetic (EM) calorimeter. Towards these goals, a 36-pad silicon sensor with an individual pad size of ∼1 cm2^2 is designed on a 4-inch high resistivity N-type wafer and fabricated at Bharat Electronics Limited, Bangalore. The sensors have been used to assemble the prototype Si-W calorimeters and were successfully tested with high-energy particle beams. The design and development of the large area silicon sensor and its characterization using radioactive sources in the laboratory and high-energy particle beams are reported in this paper.We present the research and development work of the first version of a 6*6 array of silicon pad detectors, carried out in India, for the proposed forward calorimeter (FOCAL) as part of the ALICE collaboration upgrade program at CERN. The primary motivation is to develop a large area silicon pad array realizing the challenging requirements of high-energy physics experiments such as low leakage current, high breakdown voltage and evaluate its performance as an active layer in the prototype silicon tungsten (Si-W) electromagnetic (EM) calorimeter. Towards these goals, a 36-pad silicon sensor with an individual pad size of 1 cm2 is designed on a 4-inch high resistivity N-type wafer and fabricated at Bharat Electronics Limited, Bangalore. The sensors have been used to assemble the prototype Si-W calorimeters and were successfully tested with high-energy particle beams. The design and development of the large area silicon sensor and its characterization using radioactive sources in the laboratory and high-energy particle beams are reported in this paper

    A wide swing charge sensitive amplifier for a prototype Si–W EM calorimeter

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    A wide swing charge sensitive amplifier (CSA) has been developed, as a part of a front-end electronics (FEE) readout ASIC, for a prototype silicon tungsten (Si–W) based electromagnetic (EM) calorimeter. The CSA, designed in 0.35μm N-well CMOS technology using 5V MOS transistors, has a wide linear operating range of 2.6 pC w.r.t the input charge with a power dissipation of 2.3 mW. A noise figure (ENC) of 820 e− at 0 pF of detector capacitance with a noise slope of 25 e−/pF has been achieved (when followed by a CR-RC2 filter of 1.2μs peaking time). This design of CSA provides a dynamic range (ratio of maximum detectable signal to noise floor) of 79 dB for the maximum input charge of 2.6 pC when connected to a silicon detector with a capacitance of 40 pF. Using folded cascode architecture-based input stage and low voltage high swing current mirrors as the load, the CSA provides an enlarged output swing by biasing the output node towards one supply rail and utilizing the voltage range towards the opposite rail. The design philosophy works for both polarities of a large input signal. This paper presents the design of CSA with a wide negative output swing for an anticipated input signal of positive polarity in the target application with a known detector biasing scheme.A wide swing charge sensitive amplifier (CSA) has been developed, as a part of a front-end electronics (FEE) readout ASIC, for a prototype silicon tungsten (Si-W) based electromagnetic (EM) calorimeter. The CSA, designed in 0.35 μ\mum N-well CMOS technology using 5V MOS transistors, has a wide linear operating range of 2.6 pC w.r.t the input charge with a power dissipation of 2.3 mW. A noise figure (ENC) of 820 e^- at 0 pF of detector capacitance with a noise slope of 25 e^-/pF has been achieved (when followed by a CR-RC2^2 filter of 1.2 μ\mus peaking time). This design of CSA provides a dynamic range (ratio of maximum detectable signal to noise floor) of 79 dB for the maximum input charge of 2.6 pC when connected to a silicon detector with a capacitance of 40 pF. Using folded cascode architecture-based input stage and low voltage high swing current mirrors as the load, the CSA provides an enlarged output swing when biasing the output node towards one supply rail and utilizing the voltage range towards the opposite rail. The design philosophy works for both polarities of a large input signal. This paper presents the design of CSA with a wide negative output swing for an anticipated input signal of positive polarity in the target application with a known detector biasing scheme

    ANUINDRA: A wide dynamic range FEE ASIC for a silicon–tungsten electromagnetic calorimeter

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    A wide dynamic range (ratio of maximum detectable signal to noise floor) front end electronics (FEE) readout ASIC ANUINDRA has been developed in 0.35μm standard N-well CMOS technology for the prototype forward calorimeter (FOCAL), a silicon–tungsten (Si–W) electromagnetic (EM) calorimeter, proposed as part of the ALICE upgrade at CERN. It is a 16 channel pulse processing ASIC with a multiplexed serial output along with all the individual channel’s responses available as output pins. Each channel consists of a charge sensitive amplifier (CSA), semi-Gaussian pulse shaper, gain-stage, and Track & Hold stage. The ASIC has been designed with a linear operating range of 2.6 pC w.r.t the input charge and a measured charge gain of 1.34 mV/fC. ANUINDRA ASIC shows a noise level (ENC) of 820 e^- with 0 pF of detector capacitance. A baseline recovery of better than 1% within 5μs can be attained by adjusting the pole–zero locations with the help of external voltage control. The fabricated and packaged ANUINDRA was successfully tested and characterized in the laboratory and with a high energy particle beam at the SPS beamline in CERN. The design details of ANUINDRA ASIC along with the test results are presented herewith in this paper

    1‑Acetylpyrene–Salicylic Acid: Photoresponsive Fluorescent Organic Nanoparticles for the Regulated Release of a Natural Antimicrobial Compound, Salicylic Acid

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    Photoresponsive 1-acetylpyrene–salicylic acid (AcPy-SA) nanoparticles (NPs) were developed for the regulated release of a natural antimicrobial compound, salicylic acid. The strong fluorescent properties of AcPy-SA NPs have been extensively used for potential in vitro cell imaging. The phototrigger capability of our newly prepared AcPy-SA NPs was utilized for the efficient release of an antimicrobial compound, salicylic acid. The photoregulated drug release of AcPy-SA NPs has been shown by the subsequent switching off and on of a visible-light source. In vitro biological studies reveal that AcPy-SA NPs of ∼68 nm size deliver the antimicrobial drug salicylic acid into the bacteria cells (<i>Pseudomonas aeruginosa</i>) and efficiently kill the cells upon exposure to visible light (≥410 nm). Such photoresponsive fluorescent organic NPs will be highly beneficial for targeted and regulated antimicrobial drug release because of their biocompatible nature, efficient cellular uptake, and light-induced drug release ability

    Changes in abundance levels of HP and AZGP on a temporal manner.

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    <p>A. Scanned blot images for these proteins at 15–60 days post injury (DPI) for the two severity groups. B. Quantification of the blots showing significant difference in expression. Comparison of abundance for HP and AZGP in complete injury (C) and incomplete injury (E), between two time periods. Quantification for the same (D, F) respectively (n = 4).</p

    Details of 31 modules generated through enrichment analysis.

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    A<p>Modules containing the proteins which show differential abundance in DIGE, and therefore, thought to represent perturbed biological pathways. <sup>B</sup>Biological processes, KEGG pathways and cellular components that are non-significant according to Hyp*<0.001, but are still listed here as they are known to be significant in other modules. For details of enrichment analysis of Biological Process, see Table-S3.</p><p>Details of 31 modules generated through enrichment analysis.</p
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