Shandong Normal University

About: Shandong Normal University is a education organization based out in Jinan, Shandong, China. It is known for research contribution in the topics: Laser & Catalysis. The organization has 12378 authors who have published 12576 publications receiving 174572 citations.

One-pot synthesis of a quantum dot-based molecular imprinting nanosensor for highly selective and sensitive fluorescence detection of 4-nitrophenol in environmental waters

Abstract: A novel molecular imprinting fluorescence nanosensor was constructed via a facile surface imprinting polymerization one-pot synthesis strategy for highly selective and sensitive recognition and detection of 4-nitrophenol (4-NP) based on an electron-transfer induced fluorescence quenching mechanism. 2-Aminoethyl methacrylate hydrochloride (AMA) was first used as a surfactant to interact with aqueous carboxyl-CdTe quantum dots (QDs) and the resultant AMA-modified QDs were used as a core support and a fluorescent signal source. Then, an ultrathin 4-NP imprinted shell (ca. 4 nm) was formed on the QD surface (i.e., QD@MIPs) by a simple facile free radical polymerization step. The one-pot synthesis simplified the imprinting process and shortened the experimental period. The imprinted sites bound the template of 4-NP efficiently through the hydrogen bonding interactions and showed excellent recognition selectivity for 4-NP over its analogues with a high imprinting factor of 9.1. The electron transfer process between QDs and 4-NP led to significant fluorescence quenching of the QD@MIPs nanosensor, by which 4-NP could be sensed, and high detection sensitivity up to 0.051 μM was attained. Furthermore, the sensor was successfully applied to determine 4-NP in seawater and lake water samples, presenting high recoveries in the range of 92.7–109.2% at three spiking levels with the relative standard deviation within 3.1–4.8%. The simple, rapid, reliable QD@MIPs-based method proved to be potentially applicable for the highly selective and sensitive fluorescence determination of trace 4-NP in complicated environmental water samples.

Multiscale Rotation-Invariant Convolutional Neural Networks for Lung Texture Classification

Abstract: We propose a new multiscale rotation-invariant convolutional neural network (MRCNN) model for classifying various lung tissue types on high-resolution computed tomography. MRCNN employs Gabor-local binary pattern that introduces a good property in image analysis—invariance to image scales and rotations. In addition, we offer an approach to deal with the problems caused by imbalanced number of samples between different classes in most of the existing works, accomplished by changing the overlapping size between the adjacent patches. Experimental results on a public interstitial lung disease database show a superior performance of the proposed method to state of the art.

Au@Cu(II)-MOF: Highly Efficient Bifunctional Heterogeneous Catalyst for Successive Oxidation–Condensation Reactions

Abstract: A new composite Au@Cu(II)-MOF catalyst has been synthesized via solution impregnation and full characterized by HRTEM, SEM-EDS, XRD, gas adsorption-desorption, XPS, and ICP analysis. It has been shown here that the Cu(II)-framework can be a useful platform to stabilize and support gold nanoparticles (Au NPs). The obtained Au@Cu(II)-MOF exhibits a bifunctional catalytic behavior and is able to promote selective aerobic benzyl alcohol oxidation-Knoevenagel condensation in a stepwise way.

Exogenous nitric oxide delays salt-induced leaf senescence in cotton (Gossypium hirsutum L.)

Abstract: Nitric oxide (NO) is a signaling molecule which plays an important role in delaying leaf senescence and increasing abiotic stress tolerance, but it is not clear if and how exogenous NO delays salt-induced leaf senescence in cotton. In this study, uniform cotton seedlings with five true main-stem leaves were cultured in hydroponics for 20 days and subjected to 150 mM NaCl. Seedlings were then treated with foliar spray of 300 μM sodium nitroprusside (SNP), a nitric oxide donor, and those with water spray were used as control. The effects of SNP on leaf senescence and expression of senescence-related genes were examined. Foliar spray with SNP significantly delayed leaf senescence in terms of the increased chlorophyll (Chl) content, photosynthetic (Pn) rate and expression of LHCB gene at 22 days after salt stress (DAS). The SNP significantly (p < 0.05) increased the expression of SOS1 and NHX1 genes and K+ content in leaves, but decreased leaf Na+ content. It also reduced (p < 0.05) the expression of ABA biosynthesis genes, NCED2, NCED9, and ABA content but increased the expression of cytokinin biosynthesis gene, IPT1 and ZR and iPA contents at 22 DAS. The overall results suggest that the delay in salt-induced leaf senescence by SNP was due to marked decrease in Na+ and ABA contents and increase in K+ and cytokinin through regulation of the expression of SOS1, NHX1, NCED2, NCED9 and IPT1 genes under salt stress. Foliar spray with SNP can be potentially useful in delaying leaf senescence, thereby increasing the economic yield of cotton under salt stress.