Enhancement of photocatalytic oxidation of humic acid in Tio?suspensions by increasing cation strength

Author name used in this publication: X. Z. Li2001-2002 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Photoelectrocatalytic degradation of humic acid in aqueous solution using a Ti/TiO?mesh photoelectrode

Author name used in this publication: X. Z. LiAuthor name used in this publication: F. B. Li2001-2002 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Heterogeneous photodegradation of pentachlorophenol and iron cycling with goethite, hematite and oxalate under UVA illumination

2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Nonesterified free fatty acids enhance the inflammatory response in renal tubules by inducing extracellular ATP release

In proteinuric renal diseases, excessive plasma nonesterified free fatty acids bound to albumin can leak across damaged glomeruli to be reabsorbed by renal proximal tubular cells and cause inflammatory tubular cells damage by as yet unknown mechanisms. The present study was designed to investigate these mechanisms induced by palmitic acid (PA; one of the nonesterified free fatty acids) overload. Our results show that excess PA stimulates ATP release through the pannexin 1 channel in human renal tubule epithelial cells (HK-2), increasing extracellular ATP concentration approximately threefold compared with control. The ATP release is dependent on caspase-3/7 activation induced by mitochondrial reactive oxygen species. Furthermore, extracellular ATP aggravates PA-induced monocyte chemoattractant protein-1 secretion and monocyte infiltration of tubular cells, enlarging the inflammatory response in both macrophages and HK-2 cells via the purinergic P2X7 receptor-mammalian target of rapamycin-forkhead box O1-thioredoxin-interacting protein/NOD-like receptor protein 3 inflammasome pathway. Hence, PA increases mitochondrial reactive oxygen species-induced ATP release and inflammatory stress, which cause a “first hit,” while ATP itself is a “second hit” in amplifying the renal tubular inflammatory response. Thus, inhibition of ATP release or the purinergic P2X7 receptor may be an approach to reduce renal inflammation and improve renal function

An Improved Method for Monitoring Multiscale Plant Species Diversity of Alpine Grassland Using UAV: A Case Study in the Source Region of the Yellow River, China.

Plant species diversity (PSD) is essential in evaluating the function and developing the management and conservation strategies of grassland. However, over a large region, an efficient and high precision method to monitor multiscale PSD (α-, β-, and γ-diversity) is lacking. In this study, we proposed and improved an unmanned aerial vehicle (UAV)-based PSD monitoring method (UAVB) and tested the feasibility, and meanwhile, explored the potential relationship between multiscale PSD and precipitation on the alpine grassland of the source region of the Yellow River (SRYR), China. Our findings showed that: (1) UAVB was more representative (larger monitoring areas and more species identified with higher α- and γ-diversity) than the traditional ground-based monitoring method, though a few specific species (small in size) were difficult to identify; (2) UAVB is suitable for monitoring the multiscale PSD over a large region (the SRYR in this study), and the improvement by weighing the dominance of species improved the precision of α-diversity (higher R 2 and lower P values of the linear regressions); and (3) the species diversity indices (α- and β-diversity) increased first and then they tended to be stable with the increase of precipitation in SRYR. These findings conclude that UAVB is suitable for monitoring multiscale PSD of an alpine grassland community over a large region, which will be useful for revealing the relationship of diversity-function, and helpful for conservation and sustainable management of the alpine grassland.Published onlin

Creation and annihilation of topological meron pairs in in-plane magnetized films

Merons which are topologically equivalent to one-half of skyrmions can exist only in pairs or groups in two-dimensional (2D) ferromagnetic (FM) systems. The recent discovery of meron lattice in chiral magnet Co8Zn9Mn3 raises the immediate challenging question that whether a single meron pair, which is the most fundamental topological structure in any 2D meron systems, can be created and stabilized in a continuous FM film? Utilizing winding number conservation, we develop a new method to create and stabilize a single pair of merons in a continuous Py film by local vortex imprinting from a Co disk. By observing the created meron pair directly within a magnetic field, we determine its topological structure unambiguously and explore the topological effect in its creation and annihilation processes. Our work opens a pathway towards developing and controlling topological structures in general magnetic systems without the restriction of perpendicular anisotropy and Dzyaloshinskii-Moriya interaction

Probing the carbon-hydrogen activation of alkanes following photolysis of Tp’Rh(CNR)(carbodiimide): a computational and time-resolved infrared spectroscopic study

Carbon–hydrogen bond activation reactions of alkanes by Tp’Rh(CNR) (Tp’ = Tp = trispyrazolylborate or Tp* = tris(3,5-dimethylpyrazolyl)borate) were followed by timeresolved infrared spectroscopy (TRIR) in the υ(CNR) and υ(BH) spectral regions on Tp*Rh(CNCH2CMe3), and their reaction mechanisms were modelled by density functional theory on TpRh(CNMe). The major intermediate species were analogs of those in the previously studied Tp’Rh(CO) alkane activations: κ3-η1-alkane complex (1); κ2-η2-alkane complex (2); and κ3-alkyl hydride (3). Calculations predict that the barrier between 1 and 2 arises from a triplet-singlet crossing and leads to the singlet κ2-Tp’Rh(CNR)(η2-alkane) with one pyrazolyl arm dechelated, and a strongly bonded alkane. Intermediate 2 proceeds over the rate-determining C-H activation barrier to give the final product 3. The carbon hydrogenactivation lifetimes measured for the Tp*Rh(CNR) and Tp*Rh(CO) fragments with four cycloalkanes (C5H10, C6H12, C7H14, and C8H16) increase with alkanes size and show a dramatic increase between C6H12 and C7H14, indicating the control that the alkane has on the rate of C-H activation. Similar step-like behaviour was observed previously in studies on cycloalkane reactions with CpRh(CO) and Cp*Rh(CO) fragments and is attribute to the wider difference in C-H bonds that appear at C7H14. However, these rhodium fragments are significantly different in terms of their absolute lifetimes, as Tp’Rh(CNR) and Tp’Rh(CO) fragments have much slower rates of C-H activation and longer lifetimes compared to those of CpRh(CO) and Cp*Rh(CO) fragments. This is in accordance with reduced electron density in dechelated κ2-η2-alkane Tp’ complexes, which stabilizes the d8 Rh(I) in a square-planar geometry and weakens the metal's ability for oxidative addition of the C-H bond. Further, the Tp’Rh(CNR) fragment has significantly slower rates of C-H activation in comparison to the Tp’Rh(CO) fragment especially for the larger cycloalkanes. This behaviour can be attributed to steric bulk of the neopentyl isocyanide ligand, which hinders the rechelation in κ2- Tp’Rh(CNR)(cycloalkane) species and results in the C-H activation without the assistance of the rechelation. On the other hand, the C-H activation in κ2-Tp’Rh(CNR)(alkane) is assisted by CNR weaker backbonding, which increases electron density on metal centre in comparison to κ2-Tp’Rh(CO)(alkane)

Bi-Functional Silica Nanoparticles Doped with Iron Oxide and CdTe Prepared by a Facile Method

Cadmium telluride (CdTe) and iron oxide nanoparticles doped silica nanospheres were prepared by a multistep method. Iron oxide nanoparticles were first coated with silica and then modified with amino group. Thereafter, CdTe nanoparticles were assembled on the particle surfaces by their strong interaction with amino group. Finally, an outer silica shell was deposited. The final products were characterized by X-ray powder diffraction, transmission electron microscopy, vibration sample magnetometer, photoluminescence spectra, Fourier transform infrared spectra (FT-IR), and fluorescent microscopy. The characterization results showed that the final nanomaterial possessed a saturation magnetization of about 5.8 emu g−1and an emission peak at 588 nm when the excitation wavelength fixed at 380 nm