Zhejiang University

About: Zhejiang University is a education organization based out in Hangzhou, Zhejiang, China. It is known for research contribution in the topics: Population & Catalysis. The organization has 161257 authors who have published 183264 publications receiving 3417592 citations. The organization is also known as: Chekiang University & Zheda.

Effect of nitrification inhibitor DMPP on nitrogen leaching, nitrifying organisms, and enzyme activities in a rice-oilseed rape cropping system.

Abstract: DMPP (3,4-dimethylpyrazole phosphate) has been used to reduce nitrogen (N) loss from leaching or denitrification and to improve N supply in agricultural land. However, its impact on soil nitrifying organisms and enzyme activities involved in N cycling is largely unknown. Therefore, an on-farm experiment, for two years, has been conducted, to elucidate the effects of DMPP on mineral N (NH4(+)-N and NO3(-)-N) leaching, nitrifying organisms, and denitrifying enzymes in a rice-oilseed rape cropping system. Three treatments including urea alone (UA), urea + 1% DMPP (DP), and no fertilizer (CK), have been carried out. The results showed that DP enhanced the mean NH4(+)-N concentrations by 19.1%--24.3%, but reduced the mean NO3(-)-N concentrations by 44.9%--56.6% in the leachate, under a two-year rice-rape rotation, compared to the UA treatment. The population of ammonia oxidizing bacteria, the activity of nitrate reductase, and nitrite reductase in the DP treatment decreased about 24.5%--30.9%, 14.9%--43.5%, and 14.7%--31.6%, respectively, as compared to the UA treatment. However, nitrite oxidizing bacteria and hydroxylamine reductase remained almost unaffected by DMPP. It is proposed that DMPP has the potential to either reduce NO3(-)-N leaching by inhibiting ammonia oxidization or N losses from denitrification, which is in favor of the N conversations in the rice-oilseed rape cropping system.

Systemic induction and role of mitochondrial alternative oxidase and nitric oxide in a compatible tomato-Tobacco mosaic virus interaction.

Abstract: The role of mitochondrial alternative oxidase (AOX) and the relationship between AOX and nitric oxide (NO) in virus-induced systemic defense to Tobacco mosaic virus (TMV) were investigated in susceptible tomato (Solanum lycopersicum) plants TMV inoculation to the lower leaves induced a rapid NO synthesis and AOX activation in upper uninoculated leaves as early as 05 day postinoculation Application of exogenous potassium cyanide (KCN, a cytochrome pathway inhibitor) at nonlethal concentrations and NO donor diethylamine NONOate (DEA/NO) to the upper uninoculated leaves greatly induced accumulation of AOX transcript, reduced TMV viral RNA accumulation, and increased the leaf photochemical quantum yield at photosystem II Pretreatment with NO scavenger almost completely blocked TMV-induced AOX induction and substantially increased TMV susceptibility Salicylhydroxamic acid (SHAM, an AOX inhibitor) pretreatment reduced the DEA/NO-induced cyanide-resistant respiration and partially compromised induced resistance to TMV Conversely, KCN and SHAM pretreatment had very little effect on generation of NO, and pretreatment with NO scavenger did not affect KCN-induced AOX induction and TMV resistance These results suggest that TMV-induced NO generation acts upstream and mediates AOX induction which, in turn, induces mitochondrial alternative electron transport and triggers systemic basal defense against the viral pathogen

A layer-by-layer assembled and carbon nanotubes/gold nanoparticles-based bienzyme biosensor for cholesterol detection

Abstract: A bienzyme biosensor for the detection of cholesterol, based on functionalized carbon nanotubes (CNTs) was fabricated through layer-by-layer (LBL) assembly technique. Being wrapped with cationic poly(allylamine hydrochloride) (PAH), the nanocomposite, multiwalled carbon nanotubes (MCNTs) mixed with gold nanoparticles (GNPs) was water soluble and positively charged. Based on reliably electrostatic interaction, bienzyme biosensor was then fabricated by LBL assembly of the positively charged nanocomposite and the negatively charged enzymes, horseradish peroxidase (HRP) and cholesterol oxidase (ChOx). The fabricated process and the electrochemical behaviors of the biosensor were investigated by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Under the optimal conditions, the bienzyme biosensor obtained the linear range from 0.18 to 11 mM, with a detection limit of 0.02 mM. The proposed biosensor exhibited good sensitivity, stability, and controllability for the detection of cholesterol.