| 1. |
- Singh, B. P., et al.
(författare)
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Experimental access to Transition Distribution Amplitudes with the PANDA experiment at FAIR
- 2015
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 51:8
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Tidskriftsartikel (refereegranskat)abstract
- Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (pi N) TDAs from (p) over barp -> e(+)e(-)pi(0) reaction with the future PANDA detector at the FAIR facility. At high center-of-mass energy and high invariant mass squared of the lepton pair q(2), the amplitude of the signal channel (p) over barp -> e(+)e(-)pi(0) admits a QCD factorized description in terms of pi N TDAs and nucleon Distribution Amplitudes (DAs) in the forward aid backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring (p) over barp -> e(+)e(-)pi(0) with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. (p) over barp -> pi(+)pi(-)pi(0) were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q(2) < 4.3 GeV2 and 5 < q(2) < 9 GeV2, respectively, with a neutral pion scattered in the forward or backward cone vertical bar cos theta(pi 0)vertical bar > 0.5 in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of 5 . 10(7) (1 . 10(7)) at low (high) q(2) for s = 5 GeV2, and of 1 . 10(8) (6 . 10(6)) at low (high) q(2) for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with PANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing pi N TDAs.
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| 2. |
- Erni, W., et al.
(författare)
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Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
- 2013
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 49:2
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Tidskriftsartikel (refereegranskat)abstract
- This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
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| 3. |
- Verma, Suresh K., et al.
(författare)
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Determining factors for the nano-biocompatibility of cobalt oxide nanoparticles : proximal discrepancy in intrinsic atomic interactions at differential vicinage
- 2021
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 23:9, s. 3439-3458
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Tidskriftsartikel (refereegranskat)abstract
- The abounding use of cobalt oxide nanoparticles (Co3O4) requires a detailed understanding of their environmental and biomedical nanotoxicity and an eminent solution to the associated hazards; molecular and atomic aspects of the subject are poorly understood. This study reconnoiters thein vitroandin vivonanotoxicity of Co3O4nanoparticles using human colon cell lines and the embryonic zebrafish model. The synthesis of Co3O4nanoparticles (G-CoONP) is delineatedviathe deployment of a medicinal herb,Calotropis gigantea, as an alternative greener solution; stable G-CoONP with a size of 41 ± 15 nm are attainable. Gas chromatography-mass spectroscopy (GCMS) analysis revealed the role of floral extract biomolecules in G-CoO NP synthesis. Thein vitroandin vivoeffects are accompanied by dose-dependent exposure at the molecular level by eliciting Sod1 and P53 genes up to 8.2 and 5.2 fold leading to a significant change in the reactive oxygen species and apoptosis level. It unraveled the toxicity of the cobalt oxide NP as increased apoptosis elicited by higher oxidative stress due to the accumulation and internalization of nanoparticles in cells and embryos. Green synthesized G-CoONP exhibited higher biocompatibility than commercial C-CoONP with reduced apoptosis and ROS in both human colon cell lines and zebrafish embryos.In silicoanalysis portrayed the intrinsic atomic interaction of Co3O4NP with cysteine, arginine, and histidine of oxidative stress (SOD1/sod1) and apoptosis (TP53/tp53) proteins leading to dysregulation of their structural and functional integrity in human and zebrafish, respectively. A proximal discrepancy in intrinsic atomic interaction due to the H-bonding and hydrophobic interaction at the differentialin vitroandin vivovicinage served as a key determinant factor for the cellular biocompatibility of Co3O4nanoparticles.
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| 4. |
- Panda, Pritam Kumar, PhD Student, 1991-, et al.
(författare)
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Molecular nanoinformatics approach assessing the biocompatibility of biogenic silver nanoparticles with channelized intrinsic steatosis and apoptosis
- 2022
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 24:3, s. 1190-1210
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Tidskriftsartikel (refereegranskat)abstract
- The developmental rapidity of nanotechnology poses higher risks of exposure to humans and the environment through manufactured nanomaterials. The multitude of biological interfaces, such as DNA, proteins, membranes, and cell organelles, which come in contact with nanoparticles, is influenced by colloidal and dynamic forces. Consequently, the ensued nano-bio interface depends on dynamic forces, encompasses many cellular absorption mechanisms along with various biocatalytic activities, and biocompatibility that needs to be investigated in detail. Addressing the issue, the study offers a novel green synthesis strategy for antibacterial AgNPs with higher biocompatibility and elucidates the mechanistic in vivo biocompatibility of silver nanoparticles (AgNPs) at the cellular and molecular levels. The analysis ascertained the biosynthesis of G-AgNPs with the size of 25 ± 10 nm and zeta potential of-29.2 ± 3.0 mV exhibiting LC50 of 47.2 μg mL-1 in embryonic zebrafish. It revealed the mechanism as a consequence of abnormal physiological metabolism in oxidative stress and neutral lipid metabolism due to dose-dependent interaction with proteins such as he1a, sod1, PEX protein family, and tp53 involving amino acids such as arginine, glutamine and leucine leading to improper apoptosis. The research gave a detailed insight into the role of diverse AgNPs-protein interactions with a unique combinatorial approach from first-principles density functional theory and in silico analyses, thus paving a new pathway to comprehending their intrinsic properties and usage.
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