Weak Coordination Promoted Regioselective Oxidative Coupling Reaction for 2,2′-Difunctional Biaryl Synthesis in Hexafluoro-2-propanol

An unprecedented weak coordination promoted dehydrogenative cross-coupling reaction has been developed by palladium catalysis, which provides a convenient access to a wide range of 2,2′-difunctional biaryls from easily accessible substrates. Both HFIP solvent and oxidants serve as the critical factors in this new reaction. A plausible mechanism involving Pd­(II)/Pd­(IV) is proposed. The reaction demonstrates excellent reactivity, broad functional-group tolerance and high yields

Weak Coordination Promoted Regioselective Oxidative Coupling Reaction for 2,2′-Difunctional Biaryl Synthesis in Hexafluoro-2-propanol

An unprecedented weak coordination promoted dehydrogenative cross-coupling reaction has been developed by palladium catalysis, which provides a convenient access to a wide range of 2,2′-difunctional biaryls from easily accessible substrates. Both HFIP solvent and oxidants serve as the critical factors in this new reaction. A plausible mechanism involving Pd­(II)/Pd­(IV) is proposed. The reaction demonstrates excellent reactivity, broad functional-group tolerance and high yields

Synthesis of Au Nanorod@Amine-Modified Silica@Rare-Earth Fluoride Nanodisk Core–Shell–Shell Heteronanostructures

We report here the synthesis of water-dispersible Au nanorod (NR)@ amine-modified silica@rare-earth fluoride (REF₃) nanodisk (ND) heteronanostructures (HNs). The HN fabricated as such represents a rational approach to the concurrent improvements in luminescence, water dispersibility, and other application-specific properties (such as those useful for photothermal therapy). A Au NR is deployed as an internal plasmonic antenna to couple the emission of rare-earth (RE) ions to the surface plasmon resonance (SPR) of the Au NR for enhanced photoluminescence. An intervening amine-modified silica shell is used to attach the ultrathin REF₃, to spatially separate them from the internal Au NR antenna, and to impart good water dispersibility all at the same time. Use of internal Au NR plasmonic antenna rather than the more common approach of external antenna may also be applied to design of other REF₃ HNs to improve the application performance

Prevalence of Anisotropic Shell Growth in Rare Earth Core–Shell Upconversion Nanocrystals

Through a series of carefully executed experiments, we discovered the prevalence of anisotropic shell growth in many upconversion NaREF₄ systems caused by a combination of factors: selective adsorption of ligands on the core surface due to the core crystal structure, ligand etching, and the lattice mismatch between core and shell components. This could lead to incomplete shell formation in core–shell nanocrystals under certain conditions. Shell growth is always faster in the <i>a</i> and <i>b</i> crystallographic directions than in the <i>c</i> direction. In the case of a larger lattice mismatch between the core and shell, shell growth only occurs in the <i>a</i> and <i>b</i> directions resulting in an oblong core–shell structure. These findings are useful for rationalizing shell-dependent emission properties, understanding the emission mechanisms in complex core–shell nanostructures, and for creating accurate models of core–shell designs for multifunctionality and optimal performance in applications

Life Cycle Water Use of Energy Production and Its Environmental Impacts in China

The energy sector is a major user of fresh water resources in China. We investigate the life cycle water withdrawals, consumptive water use, and wastewater discharge of China’s energy sectors and their water-consumption-related environmental impacts, using a mixed-unit multiregional input–output (MRIO) model and life cycle impact assessment method (LCIA) based on the Eco-indicator 99 framework. Energy production is responsible for 61.4 billion m³ water withdrawals, 10.8 billion m³ water consumption, and 5.0 billion m³ wastewater discharges in China, which are equivalent to 12.3%, 4.1% and 8.3% of the national totals, respectively. The most important feature of the energy–water nexus in China is the significantly uneven spatial distribution of consumptive water use and its corresponding environmental impacts caused by the geological discrepancy among fossil fuel resources, fresh water resources, and energy demand. More than half of energy-related water withdrawals occur in the east and south coastal regions. However, the arid north and northwest regions have much larger water consumption than the water abundant south region, and bear almost all environmental damages caused by consumptive water use

Life Cycle Water Use of Energy Production and Its Environmental Impacts in China

The energy sector is a major user of fresh water resources in China. We investigate the life cycle water withdrawals, consumptive water use, and wastewater discharge of China’s energy sectors and their water-consumption-related environmental impacts, using a mixed-unit multiregional input–output (MRIO) model and life cycle impact assessment method (LCIA) based on the Eco-indicator 99 framework. Energy production is responsible for 61.4 billion m³ water withdrawals, 10.8 billion m³ water consumption, and 5.0 billion m³ wastewater discharges in China, which are equivalent to 12.3%, 4.1% and 8.3% of the national totals, respectively. The most important feature of the energy–water nexus in China is the significantly uneven spatial distribution of consumptive water use and its corresponding environmental impacts caused by the geological discrepancy among fossil fuel resources, fresh water resources, and energy demand. More than half of energy-related water withdrawals occur in the east and south coastal regions. However, the arid north and northwest regions have much larger water consumption than the water abundant south region, and bear almost all environmental damages caused by consumptive water use

Experimental and Numerical Studies on a One-Step Method for the Production of Mg in the Silicothermic Reduction Process

In this paper, a new efficient one-step technical method was first developed for the production of magnesium in the industry. The one-step method could combine the two processes of dolomite decomposition and magnesium reduction in the magnesium reduction retort. Thus, the high-temperature carbon dioxide produced by the dolomite decomposition process could be collected in a timely manner instead of being emitted into the atmosphere, and excessive heat loss caused by the two separate processes also could be almost completely avoided. This paper presents an experimental study on the intrinsic chemical kinetics mechanisms of this new efficient one-step technology. By applying each of the most likely solid-state kinetic models, the kinetic parameters of the two reactions that reacted during the dolomite decomposition stage and magnesium reduction stage were evaluated, and the kinetic models that best verify the experimental data were attempted. For the dolomite decomposition stage of the one-step technology, the equation of the chemical kinetic model can be represented by α²/2 = <i>k</i>_D1τ in the temperature range of 1173–1473 K, and the apparent activation energy was determined to be 160.6 kJ mol^–1. For the magnesium reduction stage of the one-step technology, the surface reaction chemical kinetic model 1 – (1 – β)^1/3= <i>k</i>_Sτ described very satisfactorily the experimental values for the different reduction temperature. Then, a one-step model incorporating the chemical reaction kinetics of the dolomite decomposition stage and the magnesium reduction stage and heat conduction was first developed. The simulations of the impact of heating temperature on the dolomite decomposition stage and magnesium reduction stage were carried out in the reduction retorts of the furnace utilizing this model. The distribution of dolomite decomposition extent in the retorts, the total extent of dolomite decomposition with time, the distribution of magnesium reduction extent in the retorts, and the total extent of magnesium reduction with time were studied in detail. The analysis showed that the one-step technology is effective in not only reducing the cycle time of dolomite decomposition stage and magnesium reduction stage but also saving energy

Biomimetic Design of Platelet Adhesion Inhibitors to Block Integrin α2β1-Collagen Interactions: II. Inhibitor Library, Screening, and Experimental Validation

Platelet adhesion on collagen mediated by integrin α2β1 has been proven important in arterial thrombus formation, leading to an exigent demand on development of potent inhibitors for the integrin α2β1-collagen binding. In the present study, a biomimetic design strategy of platelet adhesion inhibitors was established, based on the affinity binding model of integrin proposed in part I. First, a heptapeptide library containing 8000 candidates was designed to functionally mimic the binding motif of integrin α2β1. Then, each heptapeptide in the library was docked onto a collagen molecule for the assessment of its affinity, followed by a screening based on its structure similarity to the original structure in the affinity binding model. Eight candidates were then selected for further screening by molecular dynamics (MD) simulations. Thereafter, three candidates chosen from MD simulations were separately added into the physiological saline containing separated integrin and collagen, to check their abilities for blocking the integrin–collagen interaction using MD simulations. Of these three candidates, significant inhibition was observed in the presence of LWWNSYY. Finally, the binding affinity of LWWNSYY for collagen was demonstrated by isothermal titration calorimetry. Moreover, significant inhibition of platelet adhesion in the presence of LWWNSYY has been experimentally validated. This work has thus developed an effective strategy for the biomimetic design of peptide-based platelet adhesion inhibitors

Phytoremediation of cadmium-trichlorfon co-contaminated water by Indian mustard (<i>Brassica juncea</i>): growth and physiological responses

In this study, the morphological and physiological responses of Brassica juncea to the stresses of Cadmium (Cd) and trichlorfon (TCF), and the phytoremediation potential of B. juncea to Cd and TCF were investigated under hydroponics. Results showed that Cd exhibited strong inhibition on biomass and root morphology of B. juncea as Cd concentration increased. The chlorophyll a fluorescence intensity and chlorophyll content of B. juncea decreased with the increased Cd concentration, whereas the malondialdehyde and soluble protein contents and superoxide dismutase activity increased. TCF with different concentrations showed no significant influence on these morphological and physiological features of B. juncea. The biomass and physiological status of B. juncea were predominantly regulated by Cd level under the co-exposure of Cd and TCF. B. juncea could accumulate Cd in different plant parts, as well as showed efficient TCF degradation performance. A mutual inhibitory removal of Cd and TCF was observed under their co-system. The present study clearly signified the physiological responses and phytoremediation potential of B. juncea toward Cd and TCF, and these results suggest that B. juncea can be used as an effective phytoremediation agent for the Cd-TCF co-contamination in water. Combined pollution of heavy metals and pesticides in agricultural water systems is a common phenomenon. In previous phytoremediation studies, limited information is available on the co-contamination of heavy metals and pesticides. In this study, we aimed to investigate the concentration-dependent morphological and physiological characteristics of B. juncea under single and co-stress of Cd and trichlorfon (TCF), and the phytoremediation ability of B. juncea to remove Cd and TCF through hydroponic experiment. B. juncea exhibited efficient removal performance of Cd and TCF alone and simultaneous exposure of both pollutants, indicating that B. juncea is an effective phytoremediation agent for the Cd-TCF co-contaminated water.</p

Table3_Expanded newborn screening for inherited metabolic disorders by tandem mass spectrometry in a northern Chinese population.DOCX

Tandem mass spectrometry (MS/MS) has been developed as one of the most important diagnostic platforms for the early detection and screening of inherited metabolic disorders (IMDs). To determine the disease spectrum and genetic characteristics of IMDs in Suqian city of Jiangsu province in the northern Chinese population, dried blood spots from 2,04,604 newborns, were assessed for IMDs by MS/MS from January 2016 to November 2020. Suspected positive patients were diagnosed through next-generation sequencing (NGS) and validated by Sanger sequencing. One hundred patients with IMDs were diagnosed, resulting in an overall incidence of 1/2,046, of which 56 (1/3,653), 22 (1/9,300), and 22 (1/9,300) were confirmed amino acids disorders (AAs), organic acids disorders (OAs), fatty acid oxidation disorders (FAODs) positive cases, respectively. The highest incidence of IMDs is phenylalanine hydroxylase deficiency (PAHD) (45 cases), with a total incidence of 1:4,546. Hot spot mutations in phenylalanine hydroxylase (PAH)-related genes are c.158G > A (24.44%), c.728G > A (16.67%), c.611A > G (7.78%), and c.331C>T (7.78%). The related hot spot mutation of the MMACHC gene is c.609G > A (45.45%). Short-chain acyl-CoA dehydrogenase deficiency (SCAD)-related ACADS gene hotspot mutations are c.164C > T (33.33%) and c.1031A > G (33.33%). Our work indicated that the overall incidence of IMDs is high, and the mutations in PAH, ACADS, and MMACHC genes are the leading causes of IMDs in Suqian city. The incidence of AAs in Suqian city is higher than in other Chinese areas. The disease spectrum and genetic backgrounds were elucidated, contributing to the treatment and prenatal genetic counseling of these disorders in this region.</p