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1.
Inorg Chem ; 63(31): 14761-14769, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39056170

ABSTRACT

The development of heterogeneous catalysts with abundant active sites is pivotal for enhancing the efficiency of photothermal CO2 conversion. Herein, we report the construction of Co2N0.67@ZIF-67 through the in situ pyrolysis of ZIF-67 under low-temperature pyrolysis conditions. During the pyrolysis process, the crystal structure of ZIF-67 is predominantly preserved concurrently with the formation of Co2N0.67 nanoparticles (NPs) within the ZIF-67 pores. The optimal catalyst Co2N0.67@ZIF-67(450,2) not only possesses high photothermal efficiency but also can efficiently activate CO2. Benefiting from these characteristics, Co2N0.67@ZIF-67(450,2) exhibited significant catalytic activity in the photocatalytic cycloaddition of CO2 and epichlorohydrin. The yield of (chloromethyl)ethylene carbonate reached 95%, which is more than 4 times higher than that of ZIF-67 under visible light irradiation (300 W·m2 Xe lamp, 3 h). This study could offer an alternative approach to enhance the photocatalytic activity of MOFs through low-temperature pyrolysis.

2.
Chem Commun (Camb) ; 60(26): 3559-3562, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38465413

ABSTRACT

A novel strategy was proposed to improve the performance of gas separation in nano-materials, by fabricating a core-shell structure out of the basic ionic liquid ([Emim]2[IDA]) and zeolitic imidazolate framework (ZIF-8). The [Emim]2[IDA]/ZIF-8 exhibits a remarkable CO2 adsorption capacity of 14 cm3 g-1 at 298 K and 20 kPa, the ideal selectivity of CO2/N2 is as high as 104 and CO2/CH4 is 348 at 298 K and 100 kPa, which are much higher than the CO2 adsorption capacity (4.3 cm3 g-1) and the selectivity (SCO2/N2 = 7.4, SCO2/CH4 = 2.7) of ZIF-8. This work could pave the way for designing advanced nanostructures tailored for gas separation.

3.
Langmuir ; 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38324784

ABSTRACT

Rational design and fabrication of metal-organic framework-derived metal oxide (MO) materials featuring a hollow structure and active support can significantly enhance their catalytic activity for specific reactions. Herein, a series of Co3O4 nanoparticles (NPs) immobilized in boron nitride (denoted as Co3O4@BN) with highly open and precisely controllable structures were constructed by an in situ self-assembly method combined with a controlled annealing process. The obtained Co3O4@BN not only possesses a hollow structure but also shows highly dispersed Co3O4 NPs and high loadings of up to 34.3 wt %. Owing to the ultrafine particle size and high dispersity, the optimized Co3O4@BN exhibits high catalytic activity for the cycloaddition of CO2 to epoxides under mild conditions (i.e., 100 °C and CO2 balloon), resulting in at least 4.5 times higher yields (99%) of styrene carbonate than that of Co3O4 synthesized by the pristine ZIF-67. This strategy sheds light on the rational design of hollow MO materials for various advanced applications.

4.
Inorg Chem ; 63(9): 4224-4232, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38364058

ABSTRACT

The cycloaddition of CO2 with epoxides driven by light irradiation is an intriguing approach to preparing cyclic carbonates. However, it remains a great challenge to achieve high photocatalytic efficiency in the absence of a cocatalyst. Herein, we explored a metal-organic-framework (MOF)-templated pyrolysis strategy to prepare uniform bromine ions/nitrogen-codoped carbon materials (Br-CN) as low-cost photocatalysts for CO2 cycloaddition. The optimal catalyst Br-CN-1-550 can be used as a photocatalyst to catalyze CO2 cycloaddition, remarkably reducing the energy consumption. As a result of its benefits of high photothermal efficiency and rich nucleophilic sites (Br ions), BN-CN-1-550 affords a 9 times higher yield of 4-(chloromethyl)-1,3-dioxolan-2-one than that of the ZIF-8-derived CN under cocatalyst-free conditions and light irradiation (300 mW·cm-2 full-spectrum irradiation, 10 h). This strategy provides a cost-effective way to obtain cyclic carbonate under cocatalyst-free conditions.

5.
Plant Physiol Biochem ; 201: 107809, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37315350

ABSTRACT

ORANGE (OR) plays essential roles in regulating carotenoid homeostasis and enhancing the ability of plants to adapt to environmental stress. However, OR proteins have been functionally characterized in only a few plant species, and little is known about the role of potato OR (StOR). In this study, we characterized the StOR gene in potato (Solanum tuberosum L. cv. Atlantic). StOR is predominantly localized to the chloroplast, and its transcripts are tissue-specifically expressed and significantly induced in response to abiotic stress. Compared with wild type, overexpression of StOR increased ß-carotene levels up to 4.8-fold, whereas overexpression of StORHis with a conserved arginine to histidine substitution promoted ß-carotene accumulation up to 17.6-fold in Arabidopsis thaliana calli. Neither StOR nor StORHis overexpression dramatically affected the transcript levels of carotenoid biosynthetic genes. Furthermore, overexpression of either StOR or StORHis increased abiotic stress tolerance in Arabidopsis, which was associated with higher photosynthetic capacity and antioxidative activity. Taken together, these results indicate that StOR could be exploited as a potential new genetic tool for the improvement of crop nutritional quality and environmental stress tolerance.


Subject(s)
Arabidopsis , Solanum tuberosum , Arabidopsis/genetics , Arabidopsis/metabolism , beta Carotene , Solanum tuberosum/genetics , Solanum tuberosum/metabolism , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Carotenoids/metabolism , Stress, Physiological/genetics , Gene Expression Regulation, Plant , Plant Proteins/genetics
6.
Molecules ; 28(5)2023 Feb 22.
Article in English | MEDLINE | ID: mdl-36903297

ABSTRACT

The continuous cropping obstacle has become the key factor that seriously restricts the growth, yield, and quality of Pinellia ternata. In this study, the effects of chitosan on the growth, photosynthesis, resistance, yield, and quality of the continuous cropping of P. ternata were investigated by two field spraying methods. The results indicate that continuous cropping significantly (p < 0.05) raised the inverted seedling rate of P. ternata and inhibited its growth, yield, and quality. Spraying of 0.5~1.0% chitosan effectively increased the leaf area and plant height of continuous P. ternata, and reduced its inverted seedling rate. Meanwhile, 0.5~1.0% chitosan spraying could notably increase its photosynthetic rate (Pn), intercellular carbon dioxide concentration (Ci), stomatal conductance (Gs), and transpiration rate (Tr), and decrease its soluble sugar, proline (Pro), and malonaldehyde (MDA) contents, as well as promoting its superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. Additionally, 0.5~1.0% chitosan spraying could also effectively enhance its yield and quality. This finding highlights that chitosan can be proposed as an alternative and practicable mitigator for alleviating the continuous cropping obstacle of P. ternata.


Subject(s)
Chitosan , Pinellia , Pinellia/metabolism , Chitosan/pharmacology , Photosynthesis , Peroxidase/metabolism , Superoxide Dismutase/metabolism , Seedlings/metabolism
7.
Int J Biol Macromol ; 222(Pt A): 783-793, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36174864

ABSTRACT

The bacterial infection and its transmission pose a great threat to life and health, which leads to the urgent development of efficient and broad-spectrum antibacterial agents. Herein, Ag/lignin layered nanoflower (Ag/EHL-CM-0.05) was synthesized by using biomass lignin as reducing and capping agents and silver nitrate as precursor. The study showed that the size distribution of Ag NPs was uniform distribution and about 20-40 nm. The crystal surface of Ag NPs was Ag (111) surface. The minimum inhibitory concentration of Ag/EHL-CM-0.05 against E. coli and S. aureus was all 7.8 µg/mL, which was the lowest of other Ag/lignin antibacterial materials and reached a level nearly as polycationic antibacterial agents. The antibacterial mechanism suggested that Ag/EHL-CM-0.05 could release OH and Ag+, which could cause bacterial death. Finally, Ag/EHL-CM-0.05 was sprayed onto the viscose fabrics by liquid-phase spray deposition method. It was found that the inhibition zone diameter of modified viscose fabrics against E. coli and S. aureus only dropped about 0.16 cm on average after friction treatment and 0.32 cm on average after washing treatment. This work provides a new idea for the design and synthesize of efficient, broad-spectrum, and bio-compatible antibacterial agents, which has important social, economic, and environmental significance.


Subject(s)
Metal Nanoparticles , Staphylococcus aureus , Escherichia coli , Lignin/pharmacology , Metal Nanoparticles/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry
8.
J Environ Sci (China) ; 119: 59-67, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35934466

ABSTRACT

Effective biomarkers are necessary to better understand the human mercury (Hg) exposure levels. However, mismatched biomarker sampling method causes extra uncertainty in assessing the risk of Hg exposure. To compare the differences between hair and fingernail, and further understand the excretion rates of methylmercury (MeHg) and inorganic mercury (IHg) via hair and fingernails, the total mercury (THg), MeHg, and IHg concentrations in paired hair and fingernail samples were investigated through paired samples collected from two typical mining areas, Wanshan mercury mine area (WMMA) and Hezhang zinc smelting area (HZSA). The positive correlation in THg, MeHg, and IHg concentrations (p <0.01) between hair and fingernail samples indicated that those two biomarkers can be corrected in application of assessing human Hg exposure. Compared to fingernails, the hair was suggested to be a more sensitive biomarker as the concentration of THg, MeHg and IHg were 2 ∼ 4 times higher than those in fingernails. Furthermore, the amounts of THg, MeHg, and IHg excreted via hair were 70 ∼ 226 times higher than that excreted via fingernails, and the hair plays a more important role than fingernails in the excretion of Hg from human bodies. Present study therefore provides some new insights to better understand the fate of human assimilated Hg.


Subject(s)
Mercury , Methylmercury Compounds , Biomarkers , Environmental Monitoring , Hair/chemistry , Human Body , Humans , Mercury/analysis , Nails
9.
Langmuir ; 37(41): 12179-12187, 2021 10 19.
Article in English | MEDLINE | ID: mdl-34632776

ABSTRACT

Avermectin (AVM) is a highly effective and safe biopesticide but is very sensitive to ultraviolet (UV) light and exhibits poor water solubility. Developing green and multifunctional adjuvants is important for the protection and controlled release of AVM. In this work, a number of water-soluble enzymatic hydrolysis lignins (W-EHLs) were prepared via grafting basic amino acids and used as emulsifiers with co-surfactants to prepare high-internal phase emulsions (HIPEs). The results showed that W-EHLs with co-surfactants could be prepared with HIPEs that contained 90 vol % green oil phases such as turpentine, and the stability of the HIPEs first increased and then decreased when the rate of grafting of basic amino acids on lignin increased from 0.26 to 1.46 mmol/g. The more polar oil droplets were less deformable due to their higher viscosity, thereby affording a stability advantage to HIPEs. Subsequently, the relations between the stability and interfacial viscoelasticity of the emulsion were effectively correlated by interfacial rheology, droplet size, and physical stability tests. The results showed that HIPEs with smaller droplets had poor fluidity and strong interfacial viscoelasticity due to their higher droplet packing density, which resulted in good macroscopic stability. Like the AVM carrier, the retention rate of AVM in HIPEs was 80.1% after UV radiation for 72 h, which represented the highest UV protection efficiency in AVM delivery systems. The release curves showed that the rate of release of AVM from HIPEs was adjusted by controlling the pH value of the medium. In addition, the release of HIPEs is completely in accord with both diffusion and the matrix erosion mechanism. The strategy could be extended to other sensitive pesticides and used to promote the development of sustainable agriculture.


Subject(s)
Amino Acids, Basic , Lignin , Biomass , Delayed-Action Preparations , Emulsions , Ivermectin/analogs & derivatives
10.
Food Funct ; 12(16): 7469-7479, 2021 Aug 21.
Article in English | MEDLINE | ID: mdl-34196335

ABSTRACT

Bacterial infections and multidrug resistance can seriously endanger the health and lives of humans, therefore the development of novel and efficient antibacterial strategies and drugs is urgently needed. Herein, a series of highly biocompatible lysine modified enzymatic hydrolysis lignins (EHL-Lys-x) were synthesized using the Mannich reaction. The sterilizing efficiency of EHL-Lys-2.0 against S. aureus and E. coli at 20 mg mL-1 is 93% and 50%, respectively, which is 26% higher than pure EHL. Quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM) analysis showed that the adsorption and adhesive force between EHL-Lys-x and bacteria increase with the increased amount of grafting of Lys on EHL owing to the increase of the electrostatic interaction between the EHL-Lys-x and bacteria, which results in an improvement in the antimicrobial activity of EHL-Lys-x. Subsequently, EHL-Lys-x combined with alkyl polyglucoside (APG) was used to stabilize the high internal phase emulsion containing curcumin (HIPEs-cur). The dispersed phase fraction of HIPE-cur is 87 vol%, which is the highest internal phase reported to date in the medical research area. The highest residual levels of curcumin in HIPEs are 60-fold, 3-fold and 5-fold compared to that in bulk oil after treatment with UV radiation, thermal emittance and after storage, respectively. The minimum inhibitory concentrations of HIPEs-cur against S. aureus and E. coli were found to be 1.56 and 6.25 mg mL-1, respectively, which are far higher than that of pure EHL-Lys-x. This strategy not only increases the chemical stability and bioavailability of curcumin, but also provides a novel method for the application of lignin in biomedical science.


Subject(s)
Anti-Bacterial Agents/pharmacology , Curcumin/pharmacology , Lignin/chemistry , Lysine/chemistry , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/chemistry , Curcumin/chemistry , Emulsions
11.
J Cell Mol Med ; 25(5): 2426-2435, 2021 03.
Article in English | MEDLINE | ID: mdl-33512770

ABSTRACT

The aim of the present study was to explore the potential mechanism underlying the involvement of CB2 in osteoporosis. Micro-CT was utilized to examine femur bone architecture. Also, real-time PCR and Western blot analysis were utilized to detect the effect of 2-AG on the expression of CB2 and Notch, or the interaction between CB2 and Notch 2. 2-AG treatment up-regulated BMD, Tb.Sp and SMI in OVX mice, whereas proportion of bone volume in total volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and bone mineral density (BMD) were decreased in 2-AG-treated OVX mice. Accordingly, 2-AG administration up-regulated Notch 1 expression in OVX mice but had no effect on CB2 and Notch 2 expression. Meanwhile, 2-AG administration promoted the differentiation of hBMSCs in OVX mice, while exhibiting no effect on the proliferation of hBMSCs. Furthermore, in the cellular models, 2-AG treatment also up-regulated Notch 1 expression but had no effect on CB2 and Notch 2 expression, while Notch 1 shRNA had no effect on CB2 and Notch 2 expression. 2-AG promoted cell proliferation and differentiation, which were inhibited by Notch 1 shRNA. NICD had no effect on CB2 level but increased Notch 1 expression, and CB2 shRNA decreased CB2 and Notch 1 expression. Finally, CB2 shRNA inhibited cell proliferation and differentiation, whereas NICD promoted proliferation and differentiation of hBMSCs. Our results provided further evidence for the association of CB2 gene with BMD and osteoporosis, and identified CB2 as a promising target for the treatment of osteoporosis.


Subject(s)
Cell Differentiation , Mesenchymal Stem Cells/metabolism , Osteoporosis/etiology , Osteoporosis/metabolism , Receptor, Cannabinoid, CB2/metabolism , Signal Transduction , Animals , Biomarkers , Bone Density , Cell Differentiation/genetics , Cells, Cultured , Disease Models, Animal , Disease Susceptibility , Humans , Immunohistochemistry , Mesenchymal Stem Cells/cytology , Mice , MicroRNAs/genetics , Osteoporosis/diagnostic imaging , Osteoporosis/pathology , Receptor, Cannabinoid, CB2/genetics , Receptors, Notch/genetics , Receptors, Notch/metabolism , X-Ray Microtomography
12.
Small ; 17(7): e2005865, 2021 02.
Article in English | MEDLINE | ID: mdl-33502106

ABSTRACT

Nanozyme-based chemodynamic therapy (CDT) has emerged as an effective cancer treatment because of its low side effects and without the requirement of exogenous energy. The therapeutic effect of CDT highlights the pivotal importance of active sites, H2 O2 supplement and the glutathione (GSH) depletion of a nanozyme. The construction of a single kind of catalyst with multiple functions for the enhanced CDT is still a big challenge. In this work, seven types of bimetallic nanoparticles are synthesized using a metal-organic framework (MOF) as a stable host instead of a Fenton or Fenton-like ions supplier. Among them, Cu-Pd@MIL-101 with an alloy loading of 9.5 wt% modified by PEG (9.5% CPMP) is found to exhibit the highest peroxidase (POD) like activity combined with a superoxide dismutase (SOD) mimic activity and the function of GSH depletion. The in vivo results suggest that the stable and ultrafine nanoparticles possess favorable CDT effect for tumor and good biosafety as well as biocompatibility. This work has provided a credible strategy to construct nanozymes with an excellent activity and may pave a new way for the design of enhanced tumor CDT treatment.


Subject(s)
Metal-Organic Frameworks , Nanoparticles , Alloys , Cell Line, Tumor , Hydrogen Peroxide
13.
ACS Appl Mater Interfaces ; 12(43): 48691-48699, 2020 Oct 28.
Article in English | MEDLINE | ID: mdl-33073975

ABSTRACT

The facile fabrication of porous solid acids is highly desired for replacing hazardous liquid acids for many acid-catalyzed reactions in the industry. Herein, we present a bottom-up strategy to construct ultrastable mesoporous Cr2O3/SiO2 nanohybrids (denoted as Meso-Cr-Si-O) with highly dispersed Lewis acid sites by pyrolysis of a SiO2@MIL-101 precursor prepared via nanocasting by a reverse double-solvent approach, which can guarantee the efficient encapsulation of SiO2 nanoparticles (NPs) inside the MIL-101 pores. The pore environment of Meso-Cr-Si-O can be well tuned by simply controlling the amount of silica within the MIL-101 pores and the pyrolysis temperature. Pyridine adsorption experiments demonstrate that the density of Lewis acidic sites in the obtained Meso-Cr-Si-O is much higher than that of MIL-101-derived Cr2O3 NPs. Benefitting from its highly mesoporous nanostructure with abundant acid sites, the optimal Meso-Cr-Si-O exhibits a significantly improved catalytic activity for the Lewis-acid-catalyzed Meerwein-Ponndorf-Verley reduction of cyclohexanone with 4.5 times higher yield of cyclohexanol than that of the MIL-101-derived Cr2O3 NPs, representing the first efficient Cr2O3-based catalytic system for this reaction.

14.
Ecotoxicol Environ Saf ; 192: 110316, 2020 Apr 01.
Article in English | MEDLINE | ID: mdl-32061981

ABSTRACT

Mercury (Hg) re-emission from sediment is an important process in the biogeochemistry cycles of Hg in the aquatic ecosystem. The contribution of Hg released from sediment to water remains unclear for some shallow lakes. Lake Nansi is a typical shallow lake in northern China that is divided into upper and lower lakes by a dam. The Hg species in the water profile and sediment were measured from two sampling sites in the lake. Nansi Lake was not markedly contaminated by Hg. The Hg profile in the sediment indicated that the demand for energy and the policy management in the catchment influenced the Hg accumulation in its sediment. On the basis of Fick's first law and the sedimentation rate, the diffusion flux of dissolved Hg from sediment to overlying water and the accumulation flux were estimated. According to one-year scale estimation, approximately 10%-13% the Hg in the sediments can be re-released into the overlying water. The Hg diffused from the sediment accounted for 7.9%-16% of the Hg in the overlying water. These results of this study improve the understanding of the sources of pollution in water and enable researchers to focus on the contribution of sediment to the pollution of water in shallow lakes.


Subject(s)
Geologic Sediments/chemistry , Lakes/chemistry , Mercury/analysis , Water Pollutants, Chemical/analysis , China , Environmental Monitoring
15.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(1): 20-26, 2019 Jan.
Article in Chinese | MEDLINE | ID: mdl-31037900

ABSTRACT

OBJECTIVE: To investigate the analgesic mechanism of xylazine by inhibiting the activation of hyperpolarized cyclic nucleotide-gated (HCN) ion channels. METHODS: HCN subchannel 1 (HCN1) knockout mice (HCN1-/-) and HCN1 wild type mice (HCN1+/+) were intraperitoneally injected with physiological saline and xylazine (10, 20, 30, and 40 mg/kg). Mechanical pain test and tail flick test were used to test the analgesic effect of xylazine by using the percentage of the maximal possible effect (%MPE); The control group and test groups of different concentrations of xylazine (12.5, 25, 50, and 100 µmol/L) were set up using HEK 293 cells transfected HCN1 plasmid and HCN subchannel 2 (HCN2) plasmid, respectively. The activated current of hyperpolarized HEK 293 cells expressing HCN1 and HCN2 ion channels and the inhibition rate of xylazine on hyperpolarization-activated currents were recorded using a whole cell patch clamp. RESULTS: The results demonstrated that %MPE of the mechanical pain stimuli test and the thermal radiation stimuli test increased with the higher concentration of xylazine injected for both HCN1+/+ mice and HCN1-/-mice. When injecting xylazine by 30 mg/kg and 40 mg/kg, the %MPE of mechanical pain stimuli test for HCN1-/- mice were %MPE= (62.06±14.72) % and %MPE= (69.92±16.09) %, respectively; and the percentages of tail flick tests were (52.50±1.97) % and %MPE= (64.74±6.34) %, respectively. But for HCN1+/+ mice, the percentages of mechanical pain stimuli test were %MPE= (75.47±8.06) % and %MPE= (86.35±11.31) %; respectively, and the percentage of tail flick tests were %MPE= (57.83±4.82) % and (74.98±9.35) %. The analgesic effect results of the mechanical pain test and tail flick test of HCN1+/+ mice were significantly different from HCN1-/- mice ( P<0.05). Whole-cell patch clamp test results showed that xylazine had inhibitory effects on the currents of HCN1 and HCN2 ion channels, and the hyperpolarization-activated currents inhibition rate of HCN1 by xylazine (12.5-100 µmol/L) was between (24.62±23.62) %- (62.40±15.48) %; V1/2 of HCN1 was between (-79.58±1.56) mV- (-98.95±3.57) mV. The Ih inhibition rate of HCN2 by xylazine (12.5-100 µmol/L) was between (29.19±17.82) %- (80.02±6.64) %; with V1/2 of HCN2 between (-102.17±1.36) mV- (-117.48±2.38) mV. CONCLUSION: Xylazine showed better analgesic effect on HCN1+/+ mice than HCN1-/- mice. Xylazine can produce analgesic effect by inhibiting HCN ion channel currents.


Subject(s)
Xylazine/pharmacology , Animals , HEK293 Cells , Humans , Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels , Mice , Nucleotides, Cyclic
16.
ACS Cent Sci ; 5(1): 176-185, 2019 Jan 23.
Article in English | MEDLINE | ID: mdl-30693336

ABSTRACT

The development of a general synthesis approach for creating fine alloyed nanoparticles (NPs) in the pores of metal-organic frameworks (MOFs) shows great promise for advanced synergetic catalysis but has not been realized so far. Herein, for the first time we proposed a facile and general strategy to immobilize ultrafine alloyed NPs within the pores of an MOF by the galvanic replacement of transition-metal NPs (e.g., Cu, Co, and Ni) with noble-metal ions (e.g., Pd, Ru, and Pt) under high-intensity ultrasound irradiation. Nine types of bimetallic alloyed NPs of base and noble metals were successfully prepared and immobilized in the pores of MIL-101 as a model host, which showed highly dispersed and well-alloyed properties with average particle sizes ranging from 1.1 to 2.2 nm and high loadings of up to 10.4 wt %. Benefiting from the ultrafine particle size and high dispersity of Cu-Pd NPs and especially the positive synergy between Cu and Pd metals, the optimized Cu-Pd@MIL-101 exhibited an extremely high activity for the homocoupling reaction of phenylacetylene under unprecedented base- and additive-free conditions and room temperature, affording at least 19 times higher yield (98%) of 1,4-diphenylbuta-1,3-diyne than its monometallic counterparts. This general strategy for preparing various MOF-immobilized alloyed NPs potentially paves the way for the development of highly active metal catalysts for a variety of reactions.

17.
Angew Chem Int Ed Engl ; 56(24): 6843-6847, 2017 06 06.
Article in English | MEDLINE | ID: mdl-28444925

ABSTRACT

A novel method for the highly efficient and reversible capture of CO in carbanion-functionalized ionic liquids (ILs) by a C-site interaction is reported. Because of its supernucleophilicity, the carbanion in ILs could absorb CO efficiently. As a result, a relatively high absorption capacity for CO (up to 0.046 mol mol-1 ) was achieved under ambient conditions, compared with CO solubility in a commonly used IL [Bmim][Tf2 N] (2×10-3  mol mol-1 ). The results of quantum mechanical calculations and spectroscopic investigation confirmed that the chemical interaction between the C-site in the carbanion and CO resulted in the superior CO absorption capacities. Furthermore, the subsequent conversion of captured CO into valuable chemicals with good reactivity was also realized through the alkoxycarbonylation reaction under mild conditions. Highly efficient CO absorption by carbanion-functionalized ILs provides a new way of separating and converting CO.


Subject(s)
Anions/chemistry , Carbon Monoxide/chemistry , Ionic Liquids/chemistry , Binding Sites , Carbon-13 Magnetic Resonance Spectroscopy , Density Functional Theory , Molecular Structure , Spectroscopy, Fourier Transform Infrared
18.
Huan Jing Ke Xue ; 38(10): 4151-4159, 2017 Oct 08.
Article in Chinese | MEDLINE | ID: mdl-29965198

ABSTRACT

As one of the drinking water sources for Guiyang City in southwest China, the Aha Reservoir has an area of 190 km2 and a volume of 5.42×108 m3. The water depth is less than 30 m, with an average depth of 13 m. Regulated by subtropical humid monsoon climate, it has cool summers and warm winters, with an annual mean air temperature of about 15.3℃ and an annual normal rainfall of approximately 1,129 mm. Impacted heavily by human activity (e.g., untreated industrial and domestic sewage and agricultural non-point pollution sources), the eutrophication problem in the Aha Reservoir has become more serious each year. In order to explore the spatial and temporal distribution characteristics of chlorophyll a (Chl-a) and its relationship to algae and the driving factors in the Aha Reservoir, phytoplankton and water samples were collected in the dry period, normal period, and flood period. The results showed a significant seasonal variation in Chl-a, same as biomass, but not the same as the algal abundance. Highest Chl-a concentration (91 µg·L-1) occurred in the mean season with the dinoflagellate bloom but during dry and wet seasons, they were only 8 µg·L-1 and 16 µg·L-1, respectively. During the dry and flood periods, the Chl-a concentrations in surface waters were slightly higher than the other layers caused by sufficient light and dissolved oxygen. But in the normal period, the Chl-a concentrations in surface waters were far higher than the other layers because of the dinoflagellate bloom assembling in surface waters. Located at the reservoir entrance of Jinzhong River, Dam sampling point owned higher Chl-a concentration than Kuzhong as a result of higher nutrients. Correlation analysis indicated that Dinoflagellate was positively correlated with Chl-a (R=0.798, P<0.01). Chl-a was positively associated with total phosphorus, dissolved oxygen, pH value, and total nitrogen (R=0.762, P<0.01; R=0.792, P<0.01; R=0.658, P<0.01; R=0.388, P<0.05) and it had a negative correlation with the N/P ratio and nitrate nitrogen (R=-0.37, P<0.05; R=-0.435, P<0.05). Stepwise regression analysis showed that TP, N/P ratio, and DO were the most important factors influencing the temporal and spatial distribution of Chl-a. Thermal stratification and water temperature were also the significant factors that could not be ignored.


Subject(s)
Chlorophyll A/analysis , Drinking Water/chemistry , Environmental Monitoring , Eutrophication , China , Dinoflagellida , Nitrogen/analysis , Oxygen/analysis , Phosphorus/analysis , Phytoplankton , Seasons , Spatio-Temporal Analysis
19.
Neurochem Res ; 41(12): 3250-3260, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27655256

ABSTRACT

Neuropathic pain (NP) is a clinically incurable disease with miscellaneous causes, complicated mechanisms and available therapies show poor curative effect. Some recent studies have indicated that neuroinflammation plays a vital role in the occurrence and promotion of NP and anti-inflammatory therapy has the potential to relieve the pain. During the past decades, mesenchymal stem cells (MSCs) with properties of multipotentiality, low immunogenicity and anti-inflammatory activity have showed excellent therapeutic effects in cell therapy from animal models to clinical application, thus aroused great attention. However there are no reports about the effect of intrathecal human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) on NP which is induced by peripheral nerve injury. Therefore, in this study, intrathecally transplanted HUC-MSCs were utilized to examine the effect on neuropathic pain induced by a rat model with spinal nerve ligation (SNL), so as to explore the possible mechanism of those effects. As shown in the results, the HUC-MSCs transplantation obviously ameliorated SNL-induced mechanical allodynia and thermal hyperalgesia, which was related to the inhibiting process of neuroinflammation, including the suppression of activated astrocytes and microglia, as well as the significant reduction of pro-inflammatory cytokines Interleukin-1ß (IL-1ß) and Interleukin -17A (IL-17A) and the up-regulation of anti-inflammatory cytokine Interleukin -10 (IL-10). Therefore, through the effect on glial cells, pro-inflammatory and anti-inflammatory cytokine, the targeting intrathecal HUC-MSCs may offer a novel treatment strategy for NP.


Subject(s)
Mesenchymal Stem Cell Transplantation , Neuralgia/therapy , Umbilical Cord/cytology , Animals , Astrocytes/metabolism , Humans , Hyperalgesia/etiology , Hyperalgesia/physiopathology , Hyperalgesia/therapy , Inflammation/etiology , Inflammation/metabolism , Inflammation/therapy , Interleukin-10/metabolism , Interleukin-17/metabolism , Interleukin-1beta/metabolism , Ligation , Male , Microglia/metabolism , Neuralgia/etiology , Neuralgia/physiopathology , Rats, Sprague-Dawley , Spinal Nerves/injuries
20.
Angew Chem Int Ed Engl ; 55(25): 7166-70, 2016 06 13.
Article in English | MEDLINE | ID: mdl-27136274

ABSTRACT

A new strategy for multi-molar absorption of CO2 is reported based on activating a carboxylate group in amino acid ionic liquids. It was illustrated that introducing an electron-withdrawing site to amino acid anions could reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group to interact with CO2 very efficiently. An extremely high absorption capacity of CO2 (up to 1.69 mol mol(-1) ) in aminopolycarboxylate-based amino acid ionic liquids was thus achieved. The evidence of spectroscopic investigations and quantum-chemical calculations confirmed the interactions between two kinds of sites in the anion and CO2 that resulted in superior CO2 capacities.

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