44 research outputs found

    Effect of Molecular Charge Asymmetry on Even-to-odd Ratio of High-order Harmonic Generation

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    Recently, asymmetric molecules, such as HeH2+_2^+, CO, OCS, HCl, have been evolved much attention since its rich information in the high-order harmonic generation (HHG), whose ratio of adjacent even and odd harmonics characterizes the asymmetry of molecules. In this paper, we study the dependence of even-to-odd ratio on the asymmetric parameters, in particular, the nuclear-charge ratio, and the permanent dipole, by exploiting a simple but general model of asymmetric molecules Z1Z2Z_1Z_2 subjected to an intense laser pulse. The HHG is simulated by the numerical method of solving the time-dependent Schrödinger equation. We find out that this even-to-odd ratio strongly depends on the nuclear-charge ratio. In particular, the even-to-odd ratio reaches its maximum when the nuclear-charge ratio is about from 0.5 to 0.7. Besides, the dependence on the permanent dipole of the even-to-odd ratio has a non-trivial law. To explain, we calculate the analytical ratio of the transition dipole according to the emission of even and odd harmonics, and this ratio is well consistent with the even-to-odd ratio of the HHG

    Design of High Isolation Dual-band MIMO Antenna Using Single Neutral Line

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    A dual-band MIMO antenna with a high isolation is presented in this paper. The proposed MIMO antenna consists of two identical E-shaped micro-strip antennas which are designed on an FR4 substrate. The antenna is designed for radiating at 2.6 GHz and 5 GHz that can be used for the applications of 4G and 5G systems, respectively. Neutral line technique is used for mutual coupling reduction between the E-shaped antenna. Good isolation characteristics are obtained by using single micro-strip line connected between two elements of MIMO antenna. The antenna is fabricated and measured, and good agreement is achieved between the experimental and simulated results

    Acetylcholinesterase activity as a biomarker of exposure to antibiotics and pesticides in the black tiger shrimp (Penaeus monodon).

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    This study aimed to assess the potentiality to use cholinesterase activity (ChE) in black tiger shrimp (Penaeus monodon) as a biomarker of exposure to 2 antibiotics (enrofloxacin, furazolidone) and 2 pesticides (endosulfan, deltamethrin), commonly used in Vietnamese farms. ChE from muscle and gills was first characterised using three different substrates and specific inhibitors. Results showed that both tissues possess only one ChE which displays the typical properties of an acetylcholinesterase (AChE). In a second part, shrimp (average weight of 8.8-10 g) were fed with medicated-feed containing 4g enrofloxacin (quinolone) or furazolidone (nitrofuran)/kg for 7 days, or exposed to 3 actual concentrations of endosulfan (0, 0.009, 0.09, 0.9 microg/L) or deltamethrin (0, 0.0007, 0.007, 0.07 microg/L) for 4 days. After treatment, animals were decontaminated during 7 days. We observed that AChE activity in muscle was not significantly affected in shrimp fed with enrofloxacin or furazolidone, while it significantly decreased (up to 28%) in gills of shrimp fed with furazolidone. Following endosulfan and deltamethrin exposure, no significant changes in AChE activity were observed in gills. However, a significant decrease occurred in muscle after 4 days exposure (inhibition of 30% and 49% at 0.9 microg/L endosulfan and 0.07 microg/L deltamethrin, respectively). While muscle AChE activity should be assessed to point out endosulfan or deltamethrin exposure, gill AChE activity impairment could indicate an exposure to furazolidone. The present study underlines the benefits to use AChE as a biomarker of chemotherapeutics as part of an integrated aquaculture management to reach industry sustainability

    Gadolinium-Cyclic 1,4,7,10-Tetraazacyclododecane-1,4,7,10-Tetraacetic Acid-Click-Sulfonyl Fluoride for Probing Serine Protease Activity in Magnetic Resonance Imaging

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    Serine protease is linked to a wide range of diseases, prompting the development of robust, selective, and sensitive protease assays and sensing methods. However, the clinical needs for serine protease activity imaging have not yet been met, and the efficient in vivo detection and imaging of serine protease remain challenging. Here, we report the development of the gadolinium-cyclic 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-click-Sulfonyl Fluoride (Gd-DOTA-click-SF) MRI contrast agent targeting serine protease. The HR-FAB mass spectrum confirmed the successful formation of our designed chelate. The molar longitudinal relaxivity (r1) of the Gd-DOTA-click-SF probe (r1 = 6.82 mM−1 s−1) was significantly higher than that of Dotarem (r1 = 4.63 mM−1 s−1), in the range of 0.01–0.64 mM at 9.4 T. The in vitro cellular study and the transmetallation kinetics study showed that the safety and stability of this probe are comparable to those of conventional Dotarem. Ex vivo abdominal aortic aneurysm (AAA) MRI revealed that this probe has a contrast-agent-to-noise ratio (CNR) that is approximately 51 ± 23 times greater than that of Dotarem. This study of superior visualization of AAA suggests that it has the potential to detect elastase in vivo and supports the feasibility of probing serine protease activity in T1-weighted MRI
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