ALBERT

Description: The extensive applications of cerium (Ce) increased the chance of human exposure to Ce and its compounds. It was reported that Ce was mainly deposited in the bone after administration. However, the potential effect and mechanism of Ce on bone metabolism are not well-understood. In this study, we investigated the cellular effects of Ce on the differentiation of mesenchymal stem cells (MSCs) and the associated molecular mechanisms. The results indicated that Ce promoted the osteogenic differentiation and inhibited the adipogenic differentiation of MSCs at cell level. Genes involved in transforming growth factor- β /bone morphogenetic proteins (TGF- β /BMP) signaling pathway were significantly changed when the MSCs were exposed to 0.0001 µM Ce by RT 2 Profiler™ PCR Array analysis. The expression of genes and proteins related to pathways, osteogenic and adipogenic biomarkers of MSCs upon interaction with Ce was further confirmed by quantitative real-time reverse transcriptase polymerase chain reaction (Q-PCR) and western blot analysis. The results suggest that Ce exerts the effects by interacting with bone morphogenetic protein receptor (BMPR) and activates TGF- β /BMP signaling pathway, leads to the up-regulation of the osteogenic master transcription factor, runt-related transcription factor 2 (Runx 2), and the down-regulation of the adipocytic master transcription factor, peroxisome proliferator-activated receptor gamma 2 (PPARγ2). Runx2, which subsequently up-regulates osteoblast (OB) marker genes collagen I (Col I) and BMP2 at early stages, alkaline phosphatase (ALP) and osteocalcin (OCN) at later stages of differentiation, thus driving MSCs to differentiate into OBs. The results provide novel evidence to elucidate the mechanisms of bone metabolism by Ce. J. Cell. Biochem. © 2012 Wiley Periodicals, Inc.

Description: Groundwater salinization has become a crucial environmental problem worldwide and is considered the most widespread form of groundwater contamination in the coastal zone. In this study, a hydrochemical investigation was conducted in the eastern coastal shallow aquifer of Laizhou Bay to identify the hydrochemical characteristics and the salinity of groundwater using ionic ratios, deficit or excess of each ions, saturation indices and factor analysis. The results indicate that groundwater in the study area showed wide ranges and high standard deviations for most of hydrochemical parameters and can be classified into two hydrochemical facies, Ca 2+ -Mg 2+ -Cl - facies and Na + -Cl - facies. The ionic ratio, deficit or excess of each ions and saturation index were applied to evaluate hydrochemical processes. The results obtained indicate that the salinization processes in the coastal zones were inverse cation exchange, dissolution of calcite and dolomite and intensive agricultural practices. Factor analysis shows that three factors were determined (Factor 1: TDS, EC, Cl - , Mg 2+ , Na + , K + , Ca 2+ and SO 4 2- , Factor 2: HCO 3 - and pH; Factor 3: NO 3 - and pH), representing the signature of seawater intrusion in the coastal zone, weathering of water–soil/rock interaction, and nitrate contamination, respectively. Copyright © 2011 John Wiley & Sons, Ltd.

Description: In this paper, we have presented the influence of precipitating energetic ions caused by electromagnetic ion cyclotron (EMIC) waves on the sub-auroral ionospheric E region during a geomagnetic storm on March 8, 2008 with observations of the Meteorological Operational (METOP-02) of the Polar Orbiting Environmental Satellites (POES), a GPS receiver in Vaasa of Finland and Finnish network of search coil magnetometers. Conjugate observations of the POES METOP-02 satellite and Finnish network of search coil magnetometers have demonstrated that enhancements of the precipitating energetic ion flux within the proton anisotropic zone are attributed to the interaction between ring current (RC) ions and EMIC waves. With enhancements of the intensity of Pc1 waves observed by search coil magnetometers, the total electron content (TEC) observed by the GPS receiver accordingly increased, meaning that the enhancement of the ionospheric electron density is attributed to the precipitation of RC ions caused by EMIC waves. The electron density profiles derived by the IRI-2007 model and with precipitating energetic protons observed by the POES METOP-02 satellite show that the energetic proton precipitation can cause the E layer peak electron density to increase from 1.62 × 10 9  m −3 to 5.05 × 10 11  m −3 by 2.49 orders of magnitude. In comparison with the height-integrated conductivities derived by the IRI-2007 model, the height-integrated Pedersen and Hall conductivities derived with precipitating energetic protons increase by 2.4 and 2.34 orders of magnitude, respectively. Our result suggests that precipitating energetic ions caused by EMIC waves can lead to an obvious enhancement of the electron density and conductivities in the sub-auroral ionospheric E region during geomagnetic storms.

Description: Si 2 N 2 O ceramics were prepared by plasma activated sintering using nanosized amorphous Si 3 N 4 powder without sintering additives within a temperature range of 1400°C–1600°C in vacuum. A mixed Si – N 4− n – O n ( n  = 0, 1…4) amorphous structure was formed in the process of sintering, and Si 2 N 2 O crystals were nucleated where the local structure was similar with Si 2 N 2 O . After sintering at 1600°C, the Si 2 N 2 O ceramic was composed of elongated plate-like Si 2 N 2 O grains and amorphous phase. The Si 2 N 2 O grains showed a width of less than 100 nm and a very high aspect ratio.

Description: There is little direct evidence for effects of soil heterogeneity and root plasticity on the competitive interactions among plants. In this study, we experimentally examined the impacts of temporal nutrient heterogeneity on root growth and interactions between two plant species with very different rooting strategies: Liquidambar styraciflua (sweet gum), which shows high root plasticity in response to soil nutrient heterogeneity, and Pinus taeda (loblolly pine), a species with less plastic roots. Seedlings of the two species were grown in sandboxes in inter- and intraspecific combinations. Nutrients were applied in a patch either in a stable (slow-release) or in a variable (pulse) manner. Plant aboveground biomass, fine root mass, root allocation between nutrient patch and outside the patch, and root vertical distribution were measured. L. styraciflua grew more aboveground (40% and 27% in stable and variable nutrient treatment, respectively) and fine roots (41% and 8% in stable and variable nutrient treatment, respectively) when competing with P. taeda than when competing with a conspecific individual, but the growth of P. taeda was not changed by competition from L. styraciflua . Temporal variation in patch nutrient level had little effect on the species’ competitive interactions. The more flexible L. styraciflua changed its vertical distribution of fine roots in response to competition from P. taeda , growing more roots in deeper soil layers compared to its roots in conspecific competition, leading to niche differentiation between the species, while the fine root distribution of P. taeda remained unchanged across all treatments. Synthesis . L. styraciflua showed greater flexibility in root growth by changing its root vertical distribution and occupying space of not occupied by P. taeda . This flexibility gave L. styraciflua an advantage in interspecific competition. Liquidambar styraciflua showed greater flexibility in root growth by changing its root vertical distribution and occupying space not occupied by Pinus taeda . This flexibility gave L. styraciflua an advantage in interspecific competition.

Description: ABSTRACT Epilepsy is a group of neurological disorders characterized by epileptic seizures. In this study, we aim to explore the role of microRNA-421 (miR-421) in hippocampal neurons of epilepsy mice via the TLR/MYD88 pathway. Forty mice were randomly served as the normal and model (established as epilepsy model) groups. Hippocampal neurons were assigned into seven groups with different transfections. The RT-qPCR and western blotting were conducted to examine the expression of miR-421 TLR2, TLR4, MYD88, Bax, Bcl-2, p53, Beclin-1 and LC3II/LC3I. Cell proliferation and apoptosis were detected by MTT and flow cytometry.MYD88 is a target gene of miR-421. Model mice showed elevated expression of TLR2, TLR4, MYD88, Bax, p53, Beclin-1 and LC3II/LC3Ibut reduced expression of miR-421 and Bcl-2. In vitro experiments reveals that overexpression of miR-421 inhibited the TLR/MYD88 pathway. Besides, overexpressed miR-421 increased cell apoptosis but declined cell proliferation. It reveals that miR-421 targeting MYD88 could inhibit the apoptosis and autophagy of hippocampal neurons in epilepsy mice by down-regulating the TLR/MYD88 pathway. This article is protected by copyright. All rights reserved

Description: Dipolarization fronts (DFs) as earthward propagating flux ropes (FRs) in the Earth's magnetotail are presented and investigated with a three-dimensional (3-D) global hybrid simulation for the first time. In the simulation, several small-scale earthward propagating FRs are found to be formed by multiple X-line reconnection in the near-tail. During their earthward propagation, the magnetic field B z of the FRs becomes highly asymmetric due to the imbalance of the reconnection rates between the multiple X-lines. At the later stage, when the FRs approach the near-Earth dipole-like region, the anti-reconnection between the southward/negative B z of the FRs and the northward geomagnetic field leads to the erosion of the southward magnetic flux of the FRs, which further aggravates the B z asymmetry. Eventually, the FRs merge into the near-Earth region through the anti-reconnection. These earthward propagating FRs can fully reproduce the observational features of the DFs, e.g., a sharp enhancement of B z preceded by a smaller amplitude B z dip, an earthward flow enhancement, the presence of the electric field components in the normal and dawn-dusk directions, and ion energization. Our results show that the earthward propagating FRs can be used to explain the DFs observed in the magnetotail. The thickness of the DFs is on the order of several ion inertial lengths, and the electric field normal to the front is found to be dominated by the Hall physics. During the earthward propagation from the near-tail to the near-Earth region, the speed of the FR/DFs increases from ~150km/s to ~1000km/s. The FR/DFs can be tilted in the GSM ( x,y ) plane with respect to the y (dawn-dusk) axis and only extend several R E in this direction. Moreover, the structure and evolution of the FRs/DFs are non-uniform in the dawn-dusk direction, which indicates that the DFs are essentially 3-D.

Description: Gastrointestinal cancers (GI) are a group of highly aggressive malignancies with heavy cancer-related mortalities. Even if continued development of therapy methods, therapy resistance has been a great obstruction for cancer treatment and thereby inevitably leads to depressed final mortality. Peritumoral cancer associated fibroblasts (CAFs), a versatile population assisting cancer cells to build a facilitated tumor microenvironment (TME), has been demonstrated exerting a promotion influence on cancer proliferation, migration, invasion, metastasis and also therapy resistance. In this review, we provide an update progress in describing how CAFs mediate therapy resistance in GI by various means, meanwhile highlight the crosstalk between CAFs and cancer cells and present some vital signaling pathways activated by CAFs in this resistant process. Furthermore, we discuss the current advances in adopting novel drugs against CAFs and how the knowledge contributing to improved therapy efficacy in clinical practice. In sum, CAFs create a therapy-resistant TME in several aspects of GI progression, although some key problems about distinguishing CAFs subpopulations and controversial issues on pleiotropic CAFs in medication need to be solved for subsequent clinical application. Predictably, targeting therapy-resistant CAFs is a promising adjunctive treatment to benefit GI patients. This article is protected by copyright. All rights reserved