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The Friedel–Crafts alkylation strategy was used to prepare a hypercrosslinked polymer catalyst, which showed superior performance towards the cycloaddition reaction of CO2 with epoxides.

We previously reported that sputum induction was more sensitive than throat swabs for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in two convalescent coronavirus disease 2019 (COVID-19) patients; however, the value and safety of induced sputum testing require further study. We conducted a prospective multi-center cross-sectional study to compare induced sputum to throat swabs for SARS-CoV-2 detection. Confirmed COVID-19 patients from six hospitals in six cities across China who received one or more negative RT-PCR result for SARS-CoV-2 were enrolled, and paired specimens (induced sputum and throat swabs; 56 cases) were assayed. In three paired samples, both the induced sputum and throat swabs were positive for SARS-CoV-2. The positive rate for induced sputum was significantly higher than for throat swabs both overall (28.6% vs 5.4%, respectively; p

Quaternary phosphine type hypercrosslinked polymer catalysts were successfully prepared using the Friedel-Crafts alkylation reactions, which benefit from the synergistic effects between the Brønsted acidity of the hydroxyl group and nucleophilicity of the Br

Economic growth and environment protection related to low-carbon emission are two important wings for a coastal city. Controlling the industrial energy consumption and carbon emission for a city level is essential for the local sustainable development. We investigate the low-carbon development for Zhuhai industrial sector from 2006 to 2016. Energy consumption, carbon emission, and industrial added value are selected as the basic parameters. Industrial energy consumption and carbon emission are calculated according to the national assessment method, and the decoupling situations are studied as well in this word. Results show that for most years, carbon emission is closely linked to energy consumption, there is little decoupling trend for these two parameters. However, energy consumption and industrial added value emerge strong or weak decoupling, and carbon emission and industrial value also have decoupling trend from 2011, which indicates the technical progress for Zhuhai industrial sector during the past ten years. The main driving forces for this decoupling trend are the adjustment of the industrial structures and the applications of energy-saving technology and schemes in the energy-intensity and carbon-intensity industrial sectors. In addition, controlling industrial energy consumption is urgently needed for the sake of carbon mitigation.

The chemical transformation of CO2 under mild conditions remains a great challenge because of its exceptional kinetic and thermodynamic stability. Two important reactions in the transformation of CO2 are the N-formylation reaction of amines using hydrosilanes and CO2, and the cycloaddition of CO2 to epoxides. Here, we report the high efficiency of bifunctional metallosalen complexes bearing quaternary phosphonium salts in catalyzing both of these reactions under solvent-free, mild conditions without the need for co-catalysts. The catalysts' bifunctionality is attributed to an intramolecular cooperative process between the metal center and the halogen anion. Depending on the reaction, this activates CO2 by permitting either the synergistic activation of Si–H bond via metal–hydrogen coordinative bond (M–H) or the dual activation of epoxide via metal–oxygen coordinative bond (M–O). The one-component catalysts are also shown to be easily recovered and reused five times without significant loss of activity or selectivity. The current results are combined with previous work in the area to propose the relevant reaction mechanisms.

A variety of unique Al(salen) complexes functionalized by imidazolium-based ionic liquid (IL) moieties with the salen ligand at the two sides of 3,3′-position have been successfully prepared, rather than familiar 5,5′-position reported previously. The catalytic activity obtained by these bifunctional catalysts could be superior to those of the binary type catalysts in the formation of five-membered heterocyclic compounds from the cycloaddition reaction of CO2 and three-membered heterocyclic compounds (including terminal epoxides and N -substituted aziridines), presumably due to the distinguished intramolecularly synergistic catalysis, which might lead to perform the cycloaddition reaction at ambient conditions and retain excellent yield and unprecedented chemo- or regioselectivity. Moreover, the polyether-based trifunctional Al(salen) catalysts with the best catalytic performance could be regenerated and reused at least eight times without any obvious decreases in catalytic activity. Finally, the kinetic investigation suggested the structure of catalysts had important influences on the catalytic activity, thereby proposing the possible reaction mechanism.

A series of new metallosalen-based ionic porous organic polymers (POPs) were synthesized for the first time using a simple unique strategy based on the free-radical copolymerization reaction. Various techniques were used to characterize the physicochemical properties of these catalysts. These well-designed materials endowed high surface area, hierarchical porous structures, and enhanced CO2 /N2 adsorptive selectivity. Moreover, these POPs having both metal centers (Lewis acid) and ionic units (nucleophile) could serve as bifunctional catalysts in the catalytic conversion of CO2 into high value-added chemicals without any additional co-catalyst under mild and solvent-free conditions, for example, CO2 /epoxides cycloaddition and Nformylation of amines from CO2 and hydrosilanes. The results demonstrated that the irregular porous structure was very favorable for the diffusion of substrates and products, and the microporous structural property resulted in the enrichment of CO2 near the catalytic centers in the CO2 -involved transformations. Additionally, the superhydrophobic property could not only enhance the chemoselectivity of products but also promote the stability and recyclability of catalysts.

A series of metalloporphyrin-based hyper-crosslinked polymers (M-HCPs: M=Al, Co, Fe, Mn) has been directly synthesized through Friedel–Crafts alkylation reactions. The M-HCPs afforded abundant permanent nanopores, high Brunauer–Emmett–Teller (BET) surface area, and exceptional CO2/N2 adsorptive selectivity. The experimental results suggested that the hollow tubular Al-HCP exhibited extraordinary catalytic performance in the solvent-free synthesis of cyclic carbonates from epoxides and CO2 by using tetrabutylammonium bromide as a cocatalyst under mild conditions, which was clearly superior to the corresponding homogeneous analogue. Surprisingly, a high turnover frequency (TOF) value of 14 880 h−1 was achieved with propylene oxide at 100 °C and 3.0 MPa, which was a promising result for industrial production compared with previously reported heterogeneous catalysts. More interestingly, Al-HCP could smoothly catalyze the cycloaddition reaction, producing the corresponding cyclic carbonates by using simulated flue gas (15 % CO2 and 85 % N2 in volume) as the raw material under ambient conditions. Moreover, Al-HCP could be readily recycled and efficiently reused more than ten times, exhibiting excellent stability.

Tannic acid (TA)/KI as a cheap, green, highly-efficient, biocompatible, and recyclable catalytic system represents the excellent synergistic effect in the cycloaddition reactions of CO2 and epoxides under solvent-free conditions, which is originated from hydrogen bonding between the hydrogen atoms of phenolic hydroxyl groups within TA and the oxygen atom of the epoxide. Therefore, it is considerable to be a sustainable methodology for the utilization of bio-resources.

A simple cooperative catalytic system was successfully developed for the solvent-free N-formylation of amines with CO2 and hydrosilanes under ambient conditions, which was composed of a Zn(salen) catalyst and quaternary ammonium salt. These commercially available binary components activated the Si-H bonds effectively, owing to the intermolecular synergistic effect between Lewis base and transition metal center (LB-TM), and subsequently facilitated the insertion of CO2 to form the active silyl formats, thereby leading to excellent catalytic performance at a low catalyst loading. Furthermore, the bifunctional Zn(salen) complexes, with two imidazolium-based ionic-liquid (IL) units at the 3,3'-position of salen ligand, acted as intramolecularly cooperative catalysts, and the solvent-regulated separation resulted in facile catalyst recycling and reuse.

Remote sensing data makes great contribution to complements the inadequacy of the instruments in the region, especially at the high elevation and with complex underlying surfaces. In the paper, downscaling models based on the relationships among the precipitation, elevation, and vegetation are used. The multiple linear regression models are established with Tropical Rainfall Measuring Mission (TRMM) 3B43 dataset, the Digital Elevation Model (DEM) from the Shuttle Radar Topography Mission (SRTM), and Normalized Difference Vegetation Index (NDVI) at a high various spatial scales. The spatial resolution of TRMM 3B43 precipitation fields were downscaled from 0.25° to 1 km during 2014–2016 in the middle part of Chinese Tianshan Mountains. The results of downscaling show better agreements with the ground measurements. The downscaling results reduce the underestimation for TRMM precipitation at Bayanbulak and Balun, and it also reduces the overestimation for TRMM at Korla. However, at Yining, the differences value between the measured data and downscaling results are increased in 2014 and 2015, whereas precision of downscaling is increasing in 2016. In general, spatial downscaling can improve the precision of TRMM precipitation data. Therefore, spatial downscaling method is a feasible approach for studying the precipitation of Chinese Tianshan Mountains; it will provide more precise precipitation data sources.

In this study, temperature, air pressure, wind speed and precipitation from 19 basic stations over Qilian Mountains are used to evaluate the applicability for reanalysis datasets (ERA5, JRA-55, ERAI and HAR) during 1980–2018. The four global reanalysis products describe the state of the near-surface climate with different performances. The results show that (1) The four reanalysis products perform pretty satisfactorily for temperature and air pressure while the precipitation with the lowest quality; (2) ERA5 outperforms for most variables in correlation coefficients, especially for wind speed, but not significantly improved than EARI of other variables; (3) Overestimate of wind speed issues in HAR were also identified as the sub-grid orographic drag scheme is not included in WRF; (4) Despite some discrepancy, a warming trend is showed with all these four products; in addition, the decade from 1990 to 1999 has the fastest warming rate.

In this work, a cationic waterborne epoxy acrylic resin (WCEA) was synthesized from bisphenol an epoxy resin, acrylic acid, acrylic acid, hydroquinone as an inhibitor, and N, N-dimethylbenzylamine (DMBA) as a catalyst. The changes of NCO groups and acid value during the synthesis process were measured by chemical titration method, and its Fourier Transform Infrared (FTIR) spectra were investigated. The results indicate that the acidified waterborne resin has great water solubility and storage stability after grafting the half-blocked isocyanate.

This study aimed to synthesize a cationic waterborne polyurethane acrylate–modified epoxy acrylic resin (CWEA) from bisphenol A epoxy resin, acrylic acid, 2,4-toluene diisocyanate, polyethylene glycol 400 (PEG-400), 2-hydroxyethyl acrylate, and hydroquinone as inhibitors and N,N-dimethylbenzylamine as a catalyst. The changes in the NCO groups and the acid value during the synthesis process were measured using the chemical titration method. This method was considered as the best method for synthesizing epoxy acrylate monoesters, with optimal reaction conditions for polyurethane acrylate–modified epoxy resin.

Introduction: Enterococci are unusual etiological agents of bacterial meningitis. Meningitis caused by Enterococcus gallinarum, especially those that occur in immunocompetent hosts, is extremely rare. Moreover, community-acquired E. gallinarum meningitis might be extremely unexpected for a clinician and therefore easily misdiagnosed and mistreated. Case Presentation: A 12-year-old boy presented with an acute onset of fever, headache and vomiting. The cerebrospinal fluid culture from lumbar puncture yielded an isolate that was identified as E. gallinarum. The therapeutic regimen was a combination therapy of rifampicin and high-dose intravenous penicillin. One day after starting treatment, the patient became afebrile. A repeated lumber puncture two weeks later showed few white blood cells in the CSF and no bacterial growth. Conclusions: This case reveals an incident of meningitis caused by E. gallinarum in an immunocompetent host. The combined therapy of rifampicin and high-dose intravenous penicillin might be effective for treatment in such a case.

A series of novel zinc complexes were prepared by covalent linkage of various imidazolium-based ionic liquid moieties with the 2,2′-bipyridine ligand on the two sides of the 4,4′-position. The zinc(II) complexes containing the rigid N-chelating ligand proved to be stable, highly efficient and easy-to-handle catalysts towards the synthesis of cyclic carbonate from epoxide and CO2 without the use of any co-catalyst or organic solvent. The catalysts can be easily recovered and reused without significant loss of activity and selectivity by control of the solvent. The kinetic study uncovered that the reaction was first-order with respect to the epoxide. Moreover, a plausible reaction mechanism was proposed, in which the zinc center could promote ring-opening of the epoxide for the synergetic effect with the anion X− in ILs.

A series of new metallosalen-based ionic porous organic polymers (POPs) were synthesized for the first time using a simple unique strategy based on the free-radical copolymerization reaction. Various techniques were used to characterize the physicochemical properties of these catalysts. These well-designed materials endowed high surface area, hierarchical porous structures, and enhanced CO

A simple cooperative catalytic system was successfully developed for the solvent-free N-formylation of amines with CO

Several 2,2′-bipyridine Zn(II) complexes functionalized by imidazolium based ionic liquids are prepared and used as catalysts for the cycloaddition reaction of CO2 and various epoxides (I) to provide cyclic carbonates (III).