Shanghai University

About: Shanghai University is a education organization based out in Shanghai, Shanghai, China. It is known for research contribution in the topics: Microstructure & Graphene. The organization has 59583 authors who have published 56840 publications receiving 753549 citations. The organization is also known as: Shànghǎi Dàxué.

Accelerating the Peroxidase-Like Activity of Gold Nanoclusters at Neutral pH for Colorimetric Detection of Heparin and Heparinase Activity

Abstract: The peroxidase-like catalytic activity of gold nanoclusters (Au-NCs) is quite low around physiological pH, which greatly limits their biological applications. Herein, we found heparin can greatly accelerate the peroxidase-like activity of Au-NCs at neutral pH. The catalytic activity of Au-NCs toward the peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation by H2O2 was 25-fold increased in the presence of heparin at pH 7. The addition of heparin not only accelerated the initial catalytic rate of Au-NCs but also prevented the Au-NCs from catalyst deactivation. This allows the sensitive colorimetric detection of heparin at neutral pH. In the presence of heparinase, heparin was hydrolyzed into small fragments, weakening the enhancement effect of catalytic activity. On the basis of this phenomenon, the colorimetric determination of heparinase in the range from 0.1 to 3 μg·mL–1 was developed with a detection limit of 0.06 μg·mL–1. Finally, the detection of heparin and heparinase activity in dilute...

A Polarization Reconfigurable Patch Antenna With Loop Slots on the Ground Plane

Abstract: This letter proposes a reconfigurable microstrip patch antenna with polarization states being switched among linear polarization (LP), left-hand (LH) and right-hand (RH) circular polarizations (CP). The CP waves are excited by two perturbation elements of loop slots in the ground plane. A p-i-n diode is placed on every slot to alter the current direction, which determines the polarization state. The influences of the slots and p-i-n diodes on antenna performance are minimized because the slots and diodes are not on the patch. The simulated and measured results verified the effectiveness of the proposed antenna configuration. The experimental bandwidths of the -10-dB reflection coefficient for LHCP and RHCP are about 60 MHz, while for LP is about 30 MHz. The bandwidths of the 3-dB axial ratio for both CP states are 20 MHz with best value of 0.5 dB at the center frequency on the broadside direction. Gains for two CP operations are 6.4 dB, and that for the LP one is 5.83 dB. This reconfigurable patch antenna with agile polarization has good performance and concise structure, which can be used for 2.4 GHz wireless communication systems.

Anticancer effects of ginsenoside Rg3 (Review).

Abstract: Cancer is a life-threatening disease with an alarmingly increased annual mortality rate globally. Although various therapies are employed for cancer, the final effect is not satisfactory. Chemotherapy is currently the most commonly used treatment option. However, the unsatisfactory efficacy, severe side-effects and drug resistance hinder the therapeutic efficacy of chemotherapeutic drugs. There is increasing evidence indicating that ginsenoside Rg3, a naturally occurring phytochemical, plays an important role in the prevention and treatment of cancer. The suggested mechanisms mainly include the induction of apoptosis, and the inhibition of proliferation, metastasis and angiogenesis, as well as the promotion of immunity. In addition, ginsenoside Rg3 can be used as an adjuvant to conventional cancer therapies, improving the efficacy and/or reducing adverse effects via synergistic activities. Ginsenoside Rg3 may be a widely applied natural medicine against cancer. To date however, there is no systematic summary available of the anticancer effects of ginsenoside Rg3. Therefore, in this review, all available literature over the past 10 years was reviewed and discussed in order to facilitate further research of ginsenoside Rg3.

Comprehensive Determination of Kinetic Parameters in Solid-State Phase Transitions: An Extended Jonhson–Mehl–Avrami–Kolomogorov Model with Analytical Solutions

Abstract: An extended Jonhson–Mehl–Avrami–Kolomogorov model with analytical solutions is developed to achieve the comprehensive determination of kinetic parameters in solid-state phase transitions. A new subexpression is given for the case of adequately small activation energy of nucleation, which is ignored in previous works. Exact or approximate analytical solutions to the expressions in this model for isothermal and non-isothermal conditions are improved by introducing the Euler integral of the first kind, which are proved to be valid, accurate, and simple for possible parameters. On the basis of this model, five kinetic parameters (pre-exponential factor, activation energy of nucleation, activation energy of growth, nucleation index, and growth index) can be comprehensively determined by simultaneous analysis of isothermal and non-isothermal experimental data. Three practical examples, including two simulated examples and one experimental example, are then presented to illustrate and validate the comprehensive ...

Porous Ni–Mn oxide nanosheets in situ formed on nickel foam as 3D hierarchical monolith de-NOx catalysts

Abstract: In this work, we successfully in situ decorated nickel foam with porous Ni–Mn oxide nanosheets (3DH-NM/NF) as 3D hierarchical monolith de-NOx catalysts via a simple hydrothermal reaction and calcination process. The catalysts were carefully examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, elemental mapping, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and NH3 temperature-programmed desorption measurements. The results indicated that the nanosheets are composed of a Ni6Mn1O8 spinel and the metal species are uniformly dispersed in bi-metal oxides. As a result, the strong synergistic effects between the Mn and Ni species have been observed. The active oxygen species, reducible species and acidity are enhanced by the in situ formation of the nanosheets on the surface of nickel foam. These desirable features of 3DH-NM/NF catalysts bring about the excellent de-NOx performance. Moreover, the 3DH-NM/NF catalysts also present good stability and H2O resistance. Based on these favorable properties, 3DH-NM/NF could be considered as a promising candidate for the monolith de-NOx catalysts.