Asymmetric Amination of Unstrained C(sp)-C(sp) Bonds.

The asymmetric functionalization of unstrained C(sp)-C(sp) bonds could be a powerful strategy to stereoselectively reconstruct the backbone of an organic compound, but such reactions are rare. Although allylic substitutions have been used frequently to construct C-C bonds by the cleavage of more reactive C-X bonds (X is usually an O atom of an ester) by transition metals, the reverse process that involves the replacement of a C-C bond with a C-heteroatom bond is rare and generally considered thermodynamically unfavorable. We show that an unstrained, inert allylic C-C σ bond can be converted to a C-N bond stereoselectively via a designed solubility-control strategy, which makes the thermodynamically unfavorable process possible.

Asymmetric Substitution by Alkynyl Copper Driven Dearomatization and Rearomatization.

Catalytic asymmetric transformations by dearomatization have developed into a widely applicable synthetic strategy, but heavily relied on the use of arenes bearing a heteroatom. In this case, the dearomatization is facilitated by the involvement of a p-orbital electron of the heteroatom. Different from the conventional substrate-dependent model, here we demonstrate that the activation by a d-orbital electron of the transition-metal center can serve as a driving force for dearomatization, and is applied to the development of a novel asymmetric alkynyl copper facilitated remote substitution reaction.

Using fly larvae to convert food waste for growing Oujiang color common carps: health risk assessment of polycyclic aromatic hydrocarbons.

The present study used Chrysomya megacephala larvae (CML) to transform food waste into safe and high-quality fish feed to substitute fish meal as a source of protein for growing Oujiang color common carps followed by a human health risk assessment of polycyclic aromatic hydrocarbons (PAHs). The results showed the ∑PAH concentration in the CML fed with food waste ranged from 50 to 370 μg kg, and the most abundant PAH compound in the CML was BaP, contributing 59-84% of ∑PAHs. The Pearson correlation analysis results indicated no correlation between the ∑PAH concentrations and the culture substrate ratio (p > 0.

[Remediation Potential of Rodin on Lead and Cadmium Contaminated Farmland Soil].

Rodin (TSK) is an energy plant that can be used as a raw material for natural rubber. The aim of this study was to examine the remediation potential of TSK to lead (Pb)- and cadmium (Cd)-contaminated farmland soil. In this study, a pot experiment was conducted, and the "Soil Environmental Quality and Agricultural Land Soil Pollution Risk Control Standard (GB 15618-2018)" was used as reference.

[Progress in the Interactions of Ozone Pollution and Other Environmental Stress on Urban Forests in China].

Ground-level ozone pollution(O) and climate change have become key global problems threatening the environment and sustainable development of urban forests. At present, various studies have assessed the O impacts on trees; however, it is difficult to accurately evaluate the complex ecological effects caused by multiple factors on the natural urban environment. In this paper, the interactions between O and carbon dioxide(CO), drought, nitrogen deposition, and warming, as well as the effects of the physiology, biochemistry, and growth of urban trees in China were reviewed.

Polycyclic aromatic hydrocarbons in street dust from different functional areas in Chengdu, China: seasonal variation and health risk assessment.

This is the first investigation that identified seasonal variation, possible sources and health risk of 16 PAHs in street dust sampled park area (PA), educational area (EA), commercial area (CA), residential area (RA), and traffic area (TA) of Chengdu, one of the new first-tier cities in China. The total PAHs (∑PAHs) concentrations of averaging over two seasons varied from 2.15 to 10.

[Emission Characteristics of Biogenic Volatile Compounds (BVOCs) from Common Greening Tree Species in Northern China and Their Correlations with Photosynthetic Parameters].

In order to understand the emission characteristics of common greening trees in Beijing and analyze their correlations with photosynthetic parameters, including the net photosynthetic rate (), stomatal conductance (), intercellular CO concentration (), and transpiration rate (), we collected samples of biogenic volatile organic compounds (BVOCs) using a dynamic sampling technique from 14 species of deciduous trees. The results showed that there were significant differences in isoprene and total BVOC emissions between family or genus levels (<0.01).

[Safety evaluation of allelochemical derivative pyrone on different millet varieties].

The development of new herbicides based on allelochemicals is a potential strategy of weed control in arable field. Pyrone, a novel derivative of tricin, has significant inhibitory effects on weeds. Its safety for crops, especially for millet that are sensitive to commercial herbicides, is still poorly understood.

Evaluation of antioxidant capacity and immunomodulatory effects of yeast hydrolysates for hepatocytes of blunt snout bream (Megalobrama amblycephala).

An in-vitro study was carried out to examine the effects of yeast hydrolysate (YH) on antioxidant capacity and innate immunity of blunt snout bream (Megalobrama amblycephala) hepatocytes. Fish primary hepatocytes were seeded at a density of 3 × 10 cells mL in 6-well tissue culture plates and treated with two different media including: 1) DMEM/F12 medium (control), and 2) YH medium [DMEM/F12 + 0.1 g L YH].

Evaluation of antioxidant capacity and immunomodulatory effects of cottonseed meal protein hydrolysate and its derivative peptides for hepatocytes of blunt snout bream (Megalobrama amblycephala).

Two in vitro trials were conducted to identify a peptide with antioxidant activity and immunoenhancement from cottonseed meal protein hydrolysate (CPH) for fish. Primary hepatocytes of Megalobrama amblycephala were treated with CPH. In experiment 1, CPH significantly increased aspartate aminotransferase (GOT), alanine aminotransferase (GPT), total superoxide dismutase (t-SOD), catalase (CAT), and lysozyme activities, as well as up-regulated SOD, CAT, antimicrobial peptides 1 (Leap 1) and Leap 2 mRNA levels (p < 0.

Bioaccumulation and health risk assessments of trace elements in housefly (Musca domestica L.) larvae fed with food wastes.

This study aimed to use food waste to culture housefly larvae, which serve as the major source of protein in fish feeds, to evaluate copper (Cu), zinc (Zn), iron (Fe), nickel (Ni), cadmium (Cd), and chromium (Cr) bioaccumulation and trophic transfer in the food chain. In addition, the potential health risk to humans of exposure to these metal elements via dietary intake of tilapia fed with housefly larvae feeds was also evaluated. The results showed the bioavailability of trace elements in dish waste to housefly larvae was lower than that in staple food waste.

[Inventory and Characteristics of Biogenic Volatile Organic Compounds (BVOCs) for 12 Deciduous Fruit Trees].

To better understand the emission of biogenic volatile organic compounds (BVOCs) in suburbs, we selected 12 typical deciduous fruit trees and conducted field sampling and laboratory analysis of BVOCs using a dynamic sampling technique. To our knowledge, details of BVOC emissions for nine of the selected fruit tree species are reported here for the first time. Emissions of BVOCs from fruit trees contained nine kinds of compounds, including hydrocarbons, alcohols, and aldehydes, of which hydrocarbons accounted for up to 39.

[Effects of Elevated Ozone on Biogenic Volatile Organic Compounds (BVOCs) Emission: A Review].

With the global increase of tropospheric ozone (O) and complex interactions between biogenic volatile organic compounds (BVOCs) emissions and tropospheric O concentrations, this review summarizes current research progress and future research prospects in terms of the effects of elevated O on BVOCs emissions. The main progress included impacts of BVOCs categories, plant functional types, O sensitivity of plants, the O stress level on the response of BVOCs emissions to single O stress, and the combined effects of elevated O and temperature, carbon dioxide (CO), drought, and nitrogen (N) deposition. Results indicated that most published results reported no change in BVOCs emissions in response to increasing O concentration.

High-fat diet induces aberrant hepatic lipid secretion in blunt snout bream by activating endoplasmic reticulum stress-associated IRE1/XBP1 pathway.

This study was conducted to understand the effect of high-fat diet challenge on lipid transport and endoplasmic reticulum stress in blunt snout bream. Ninety fish (average weight: 41.84 ± 0.

Occurrence and distribution of phthalate esters in freshwater aquaculture fish ponds in Pearl River Delta, China.

The concentrations, congener profiles and spatial distribution of 13 phthalate esters (PAEs) in the freshwater fish ponds in the Pearl River Delta (PRD) region were investigated in water and sediment samples collect from 22 sites during Jul. 2016-Sept. 2017.

High-fat-diet-induced inflammation depresses the appetite of blunt snout bream (Megalobrama amblycephala) through the transcriptional regulation of leptin/mammalian target of rapamycin.

The aim of this article was to investigate the mechanism of appetite suppression induced by high-fat diets (HFD) in blunt snout bream (Megalobrama amblycephala). Fish (average initial weight 40·0 (sem 0·35) g) were fed diets with two fat levels (6 and 11 %) with four replicates. HFD feeding for 30 d could significantly increase the weight gain rate, but feeding for 60 d cannot.

Effects of partial replacement of fish meal by yeast hydrolysate on antioxidant capability, intestinal morphology, and inflammation-related gene expression of juvenile Jian carp (Cyprinus carpio var. Jian).

This study aimed to evaluate the effects of fish meal (FM) replacement by yeast hydrolysate (YH) on liver antioxidant capability, intestinal morphology, and inflammation-related genes of juvenile Jian carp (Cyprinus carpio var. Jian). A total of 600 fish (average initial weight 19.

Fishmeal replacement by rice protein concentrate with xylooligosaccharides supplement benefits the growth performance, antioxidant capability and immune responses against Aeromonas hydrophila in blunt snout bream (Megalobrama amblycephala).

This study aimed to investigate the effects of fishmeal (FM) replacement by rice protein concentrate (RPC) with a xylooligosaccharides supplement on the growth performance, antioxidant capability and immune response against Aeromonas hydrophila in blunt snout bream (Megalobrama amblycephala). Fish (46.85 ± 0.

Characteristics and health risk assessment of heavy metals exposure via household dust from urban area in Chengdu, China.

To investigate the characteristics of heavy metals (Cr, Cd, Pb, Zn, Cu and Ni) in household dust in urban household environment of Chengdu, China, 90 household dust samples were collected from 6 districts of the city. The information of houses and residents were also recorded during dust sampling to identify the correlations between heavy metals in household dust and the house attributes. And also the principal component analysis and cluster analysis for sources and impactor factors.

Spraying Brassinolide improves Sigma Broad tolerance in foxtail millet (Setaria italica L.) through modulation of antioxidant activity and photosynthetic capacity.

To explore the role of Brassinolide (BR) in improving the tolerance of Sigma Broad in foxtail millet (Setaria italica L.), effects of 0.1 mg/L of BR foliar application 24 h before 3.

Pollution characteristics and risk assessment of human exposure to oral bioaccessibility of heavy metals via urban street dusts from different functional areas in Chengdu, China.

Urban street dusts were collected in commercial area (CA), traffic area (TA), educational area (EA), residential area (RA) and parks area (PA) of Chengdu, China, to investigate the concentrations of heavy metals (Pb, Zn, Cu, Ni, Cd and Cr), and analyzed to evaluated possible sources and health risk assessment. The average concentrations (mg/kg) of Pb (82.3), Zn (296), Cu (100), Cd (1.

Research on Root Responses to Pb and Zn Combined Stress of Carex putuoshan.

Pb hyper-accumulated Carex putuoshan was taken as experimental material and subjected to combined stress of Pb and Zn. The differential expression of proteins in their roots were analyzed by Proteomic Approach. The protein that was directly involved in the cellular defense under the Pb and Zn combined stress was separated, and expression of those genes was analyzed with Carex Evergold as control.