Search

The Keggin‐type P‐Mo‐W polyoxometalate‐based ionic liquids ([VimAm]Br‐POM, POM is PMo6W6O40) were facilely supported on the green fiber (CA) to obtain a kind of bar‐shaped catalyst. The [VimAm]Br‐POM@CA showed an outstanding oxidative desulfurization performance for model oil and real oils with H2O2 as oxidant, mainly due to the dual role of the [VimAm]Br‐POM with the high activity and its excellent dispersion on CA. The dibenzothiophene (DBT) in model oil could be almost completely removed with [VimAm]Br‐POM@CA‐2 in 60 min at 60 °C without adding other extractants, in which [VimAm]Br acts as this role. Meanwhile, the influences of reaction temperature, molar ratio of H2O2/S, catalyst dosage, and different sulfur‐containing compounds were also investigated. Interestingly, the pretty low activation energy (0.1875 kJ/mol) has been achieved, and no significant loss of activity even after being reused for 5 cycles. The combination of IL‐POM and CA is an efficient strategy to obtain a newly kind desulfurization catalyst, with remarkable results on catalytic efficiency and reuse ability at the same time. [ABSTRACT FROM AUTHOR]

Nine new lanthanide coordination polymers, namely, [La 2 (MPIP) 2 (1,3-bdc) 3 ] n ‧5 n H 2 O (1) [Nd 2 (MPIP) 2 (1,3-bdc) 3 ] n ‧7 n H 2 O (2) , [Yb 2 (MPIP)(1,3-bdc) 3 ] n (3) , [Eu 2 (MPIP) 2 (1,3-bdc) 2 (CH 3 COO) 2 ] n (4) , [Ln 2 (MPIP) 2 (1,3-bdc) 2 (NO 3) 2 ] n ‧3 n H 2 O (Ln = Tb (5), Gd (6)), [Ln 2 (MPIP) 2 (1,3-bdc) 3 ] n ‧2 n H 2 O (Ln = Dy (7), Ho (8), Er (9)), MPIP = 2-(3-methylphenyl)imidazo(4,5-f)(1,10)-phenanthroline, H 2 (1,3-bdc) = benzene-1,3-dicarboxylic acid) have been synthesized under hydrothermal or solvothermal conditions and characterized by IR spectra, elemental analyses, powder X-ray diffraction and single crystal X-ray diffraction. Compounds 1 – 9 features 1D or 2D lanthanide isophthalate structures bearing large conjugated imidazophenanthroline derivative ligands. The thermal stabilities and luminescence properties of compounds 1 – 9 were investigated. Based on fluorescence sensing behavior, compounds 4 and 5 display a highly sensitive response toward Fe3+ ion through significant fluorescence quenching. Meanwhile, compound 5 can be used as an indicator to detect acidic and alkali environments. The white light emission was studied by heterogeneous physical mixing components of compounds 1 , 4 and 5. Nine new lanthanide coordination polymers based on 2-(3-methylphenyl)imidazo-(4,5-f)(1,10)-phenanthroline and benzene-1,3-dicarboxylic acid have been successfully synthesized. Compounds 1 – 9 exhibit a 1D or 2D lanthanide isophthalate structures bearing large conjugated imidazophenanthroline derivative ligands. Compounds 4 and 5 can be potential crystalline materials for detecting Fe3+ ion. Meanwhile, compound 5 can be used as an indicator to detect acid and alkali environments. In addition, white-light emission was obtained by heterogeneous physical mixing components of compounds 1 , 4 and 5. Image 1 [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effect of Scutellaria baicalensis stem-leaf total flavonoid (SSTF) on the dopaminergic neurons in the substantia nigra in a mouse model of Parkinson's disease (PD). The mouse model was established by intravenous injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). SSTF (5 mg/kg) was administered to the mice before or after MPTP injection, and the effects of SSTF on the behavior of the mice and the dopaminergic neurons in the substantia nigra were assessed. In addition, the level of serum malondialdehyde (MDA) was measured. Following injection of MPTP, the number of dopaminergic neurons in the substantia nigra was decreased and the neurons appeared atrophic. In addition, the level of serum MDA in the MPTP mice increased. The mean behavioral scores and the number of dopaminergic neurons in the SSTF treatment groups were significantly higher than in the MPTP group (P<0.05), and the mean serum MDA levels were significantly lower (P<0.05). Thus, SSTF improves the behaviors and the numbers of dopaminergic neurons in the substantia nigra in MPTP-induced PD in mice. These beneficial effects appear to be associated with the reduction in serum MDA. [ABSTRACT FROM AUTHOR]

Objectives: The protective effect of estrogen on the neurons in Parkinson's disease (PD) is unclear. The present study aimed to investigate the effect of estrogen on the apoptosis and dopaminergic function on a cultured cell model of PD. Methods: The PD model was established by addition of 1-methyl-4-phenylpyridinium (MPP+) to PC12 cell culture. Estrogen was added to cell groups with MPP+ (Estrogen+MPP+), and without MPP+ (Estrogen only group). Cell viability, content of tyrosine hydroxylase (TH), apoptosis ratio, expression of apoptosis-suppression protein Bcl-x and apoptosis-acceleration protein IL-1 beta converting enzyme (ICE) were measured. Results: Cell viability in the Estrogen+MPP+ group was similar to the control group but was higher than in the MPP+ group (P<0.05). The apoptosis ratios in the Estrogen+MPP+ group (33.6%), and the control group (31.3%), were also similar, but it was lower than in the MPP+ group (63.5%, P<0.05). Concentrations of Bcl-x were higher in the Estrogen+MPP+ group, whereas ICE concentrations were lower than in the MPP+ group (P<0.05). Conclusions: Estrogen suppresses apoptosis and improves cell viability in MPP+ induced injuries in the PC12 cells. The beneficial effects of estrogen on the PD model are due to the suppression of pro-apoptotic protein ICE, and stimulation of anti-apoptotic protein Bcl-x. [ABSTRACT FROM AUTHOR]

• Soil nitrogen content and isotope values changed after cropland abandonment. • Mineralization is more active in karstic topsoil than in the deep soil layer. • The loss NO 3 – mainly originated from the cropland topsoil in present karst areas. • Land use change from cropland to forest can reduce soil N loss to aquatic system. A large amount of cropland in the Southwestern (SW) China karst area has been abandoned since the implementation of the Grain for Green project at the end of the last century, which significantly impacted the biogeochemistry cycle in soil. However, the effect of cropland abandonment on the soil nitrogen (N) cycle and the N loss process is still little understood. N content and isotope analysis were used to assess karst soil's N fate and explore the N loss process in SW China. Soil samples were collected from four land uses, cropland (CR), abandoned CR (AC), shrubland and grassland (SG), and secondary forest (SF), by seasonal in a typically mixed land-use karst catchment at six soil depths. The results showed that the average soil particulate organic N (PON) content increased from 1.58 ± 0.49 g kg−1 to 2.70 ± 1.82 g kg−1, whereas average dissolved nitrate (NO 3 –-N) content decreased from 10.77 ± 8.87 mg kg−1 to 1.72 ± 1.84 mg kg−1 during revegetation. There was a decreasing amount of PON and dissolved N (NH 4 +-N、NO 3 –-N、TDN) content from surface to the bottom of the soil profile and large variation mainly occurred in 0 – 30 cm in the soil profiles of four different land uses, which suggests N transformation mainly occurred in topsoil (<30 cm). Mineralization was the major nitrogen transformation process that affected PON content and δ15N-PON values. The highest δ15N-PON fractionation (-5.0‰) in the soil profiles of the four types of land use caused by mineralization was detected in SF. Variation of N content and isotope values in soil profiles after cropland abandonment suggested that the loss of NO 3 –-N in karst catchment mainly came from the topsoil of cropland. Overall, N loss from the topsoil of cropland should pay more attention, while cropland abandonment can effectively reduce the loss of dissolved N from the thin karst soil layer. [ABSTRACT FROM AUTHOR]

A comprehensive experiment of characterization of the electrochemical properties of the metal oxide coatings was designed. Taking RuO2 and (Ru,La) OX as object which are coated by thermal decomposition of the metal chlorides, the effects of rare earth element La on electrochemical properties of the coatings were investigated using Tafel curves (PC), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that Ru-La oxide coatings exhibit largely exchange current density, lower polarization resistance, and more number of surface active site. It leads to the increase of electrocatalytic activity of the coatings. This experimental design not only fully has motivated the study enthusiasm and exploration spirit of students, but also has correlated theories to practical experiments by carrying out a project, it also helped the students to develop the ability of critical thinking and problem solving based on what they learned. It provided reference of teaching reform of material designed synthesis experiment. [ABSTRACT FROM AUTHOR]

Six new Zn/Cd coordination polymers (CPs) based on a new terpyridine derivative ligand, namely, [ZnLCl] n · n H 2 O ( 1 ), [ZnL 2 ] n ( 2 ), [CdL 2 (H 2 O) 2 ] n ( 3 ), [CdL 2 (H 2 O)] n ( 4 ), [Cd 2 L 2 ( m -bdc)(H 2 O) 2 ] n ( 5 ), [Cd 2 L 2 ( m -bdc)(H 2 O)] n ( 6 ), (H 2 ( m -bdc) = benzene-1,3-dicarboxylic acid, HL = 4′-(2-carboxyphenyl)-3,2′:6′,3″-terpyridine), have been synthesized under hydrothermal conditions and characterized by elemental analyses, infrared spectra, single-crystal X-ray diffraction. Compound 1 displays a 3D utp topology based on left- and right-handed helical chains. Compounds 2 , 3 and 4 are three kinds of 1D loop chain structures. Compound 5 features a (3,6)-connected 3D topology with point symbol of {4 2 ·6} 2 {4 4 ·6 2 ·8 8 ·10}. Compound 6 reveals a (3,6,8)-connected 3D framework with point symbol of {4·5 2 } 2 {4 8 ·5 6 ·6 8 ·7 4 ·8·9}{4 8 ·6 6 ·7}. Luminescent properties of compounds 1 – 6 at room temperature were investigated. [ABSTRACT FROM AUTHOR]

Special hydrological structures coupled with rainfall and agricultural activities have great impacts on water quality in karst areas. High-frequency hydro-chemical, dual nitrate isotopes and a Bayesian mixing model (SIAR) were employed to investigate the effect of heavy rainfall events on nitrogen patterns in surface and underground streams and explore the implications for nitrogen pollution prevention in a typical karst agricultural catchment in Southwest China. The results showed that [NO 3 --N] was relatively high in both surface and underground streams and the average value in surface stream was two times higher than in underground stream. The lowest [NO 3 --N] of underground stream was found in the falling limb of the hydrograph. According to source apportionment by SIAR, chemical fertilizer was the dominant nitrate source in the study area, which contributed 52–81% and 29–78% of nitrate in surface stream and underground stream, respectively. The highest dissolved inorganic nitrogen flux and [NO 3 --N] in surface stream was 5.7 times and 2.4 times higher, respectively, than in underground stream over the same period, which suggested that surface runoff rather than underground stream was the main route of rapid nitrogen loss in the karst catchment during heavy rainfall events. Reasonably planning the fertilization time and optimizing nitrogen fertilizer use should be considered to decrease nitrogen loss from farmland. Rational use of a widespread karst underground conduit system to reduce water nitrogen content may also be a potential method for achieving nitrogen removal. • Nitrogen patterns in agricultural surface and underground streams were investigated. • Nitrate in surface and ground flows mainly origin from chemical fertilizer. • Karst surface runoff was the main route of rapid nitrate loss during rainfall events. • Karst agricultural water management should consider the structure characteristics. [ABSTRACT FROM AUTHOR]

Reaction of hydrated lanthanide (III) nitrates and 4'-(3-carboxyphenyl)-4,2′:6′,4″-terpyridine (HL) under hydrothermal conditions in the presence of auxiliary ligands afforded four series of lanthanide coordination polymers, [Ln 2 (L) 2 (ox) 2 (H 2 O) 2 n (Ln ​= ​Sm (1), Eu (2)), [Ln(L)(glu)] n (Ln ​= ​Eu (3)), [Ln(L)(adip)(H 2 O)] n (Ln ​= ​Pr (4), Sm (5)), [Ln 2 (L) 2 (1,3-bdc) 2 n (Ln ​= ​Pr (6), Nd (7), Sm (8), Eu (9)), where H 2 ox, H 2 glu, H 2 adip and H 2 (1,3-bdc) denote oxalic acid, glutaric acid, adipic acid and benzene-1,3-dicarboxylic acid, which have been characterized by elemental analysis, IR and single crystal X-ray diffraction. Compounds 1 and 2 possess similar structures and display a two dimensional 6-connected hxl net ground on loop-like binuclear Ln 2 units with the (36·46·53) topology. Compound 3 presents a fascinating 3D framework with paddle-wheel units, which exhibits a 2-nodal (3,10)-connected 3,10-T9 net with (418·624·83)(43) 2 topology. Isostructural compounds 4 and 5 exhibit a (3,6)-connected kgd net with (43) 2 (46·66·83) topology. Isomorphous 6 – 9 feature a 3D (3,10)-connected 3,10 - T9 net with (418·624·83)(43) 2 topology. The structural diversity adequately demonstrate the abundant coordination chemistry of carboxylate terpyridine derivatives and the coordination geometries of LnIII ions, as well as the effects of introducing auxiliary ligands. Moreover, detailed discussion toward the photoluminescence and thermal stabilities of 1 – 9 were also conducted. Four series of lanthanide coordination polymers based on 4'-(3-carboxyphenyl)-4,2′:6′,4″-terpyridine and auxiliary ligands have been successfully synthesized under hydrothermal conditions and characterized by elemental analysis, IR and single crystal X-ray diffraction. Their thermal stabilities and luminescence properties were also investigated. Image 1 [ABSTRACT FROM AUTHOR]