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Earthquake-induced landslides are complex dynamic processes, a better understanding of which can be achieved by studying the entire dynamic process, including the propagation of seismic waves, cracking, instability, movement, and deposition. This paper explores the entire dynamic process in combination with the propagation of seismic waves and crack developing process of the slope under earthquake actions, while taking into account the strength attenuation, the major factor that causes the high-speed and long-runout movement. In this study, a simulation analysis tool called discontinuous deformation analysis (DDA) was used and improved by incorporating a seismic input method based on a viscous boundary and the free-field theory, virtual and real joints, and a shear strength attenuation criterion, to conduct a unified simulation analysis of the whole dynamic process of earthquake-induced landslide, and to analyze the influence of the dynamic response law on the instability and motion of landslide. Based on these improvements, the Donghekou landslide caused by the Wenchuan earthquake in 2008 was simulated. The dynamic characteristics of the slope showed an obvious amplification effect. At places with strong dynamic responses, cracks initiated rapidly. The progressive crack developing process of the landslide was represented. Owing to the low-friction effect, the speed increased sharply after the landslide began, promoting its high speed and long runout. From the crack propagation in the slope and the formation process of the sliding surface, it is evident that the Donghekou landslide was a typical tension-cracking and shearing sliding landslide. Highlights: The entire dynamic process analysis landslide method, from continuous to discontinuous, was established. The influence of the site dynamic response to the formation of a landslide was considered. The instability mechanism of a landslide was analyzed based on the fragmentation process. [ABSTRACT FROM AUTHOR]

It has been shown that there exist unextendible product bases (UPBs) with sizes of 6, 8, 9, and 10 in the 5-qubit system. These product vectors are not UPB any more when they are regarded as product vectors in the coarsened systems (i.e., some subsystems are merged, e.g., if two subsystems are merged, the system becomes 2 ⊗ 2 ⊗ 2 ⊗ 4 ). In this paper, we show that these product states can be expanded to UPBs in the coarsened system by adding some product vectors. Comparing with the existing UPBs, we get a series of novel UPBs which have different sizes or have the same size as that of the existing ones but are not equivalent to them. [ABSTRACT FROM AUTHOR]

Currently, the dynamic behavior of high-speed long-runout landslides triggered by earthquakes remains unclear due to the complexity of such phenomena. Degradation in the shear strength of rock masses is considered a primary factor contributing to the high velocities and long runout distances of these landslides. In this study, the strength degradation induced by changes in rock joint morphology is analyzed considering a numerical model of the Donghekou landslide, by using discontinuous deformation analysis (DDA). First, an exponential joint roughness degradation function (i.e., JRCm) that depends on displacement is incorporated with the nonlinear Barton–Bandis (B–B) shear strength criterion, and this modified B–B criterion is combined with the DDA. Moreover, a virtual joint is introduced in the DDA to model the propagation of cracks in intact rock masses, in order to simulate the dynamic phenomenon of earthquake-induced landslides. Subsequently, this improved DDA (IDDA) is validated via simulations of a shear test and a sliding block over an inclined plane. Finally, the IDDA is employed to simulate the Donghekou landslide, which was induced by the 2008 Wenchuan earthquake in China. Furthermore, the entire dynamic process of the landslide, including crack propagation, instability, initiation, and motion, is depicted. The simulated deposit patterns obtained via the IDDA are in good agreement with the results of field investigations. The simulation results also prove that the IDDA can reflect key movement behaviors of Donghekou landslide and that the degradation of rock joints significantly influences the long runout distance and high velocity of sliding mass. [ABSTRACT FROM AUTHOR]

Edge-to-edge is the most common form of contact in a two-dimensional joint block system. Discontinuous deformation analysis (DDA) is a powerful tool for handling block systems and treats an edge-to-edge contact as two vertex-to-edge contacts with a couple of normal and shear springs at the extremes of the contact segment. However, this method is unsuitable for evaluating the tensile failure of a joint under asymmetrical tension conditions, even though it can simplify the contact type and increase computational efficiency. This is mainly because the distributed forces at an edge-to-edge contact are simplified as two couples of concentrated forces. To solve this problem, this paper proposes incorporating a multi-spring edge-to-edge contact model with DDA. In the model, several contact pairs with normal and shear springs on an edge-to-edge contact are set to simulate the distributed forces. Several benchmark tests were performed to demonstrate the discrepancy between the original and improved DDAs. The results revealed that the latter more accurately models the stress distribution across the edge-to-edge contact, providing a more reasonable acceleration required to topple a series of blocks resting on an inclined stepped base. [ABSTRACT FROM AUTHOR]

Introduction: Acute respiratory distress syndrome (ARDS) is a life-threatening medical condition. It is characterized by serious lung inflammation or injury. Characterizing novel miRNAs implicated in ARDS pathogenesis may provide new therapeutic strategy for managing ARDS. Methods: We employed LPS-induced lung injury model to profile miRNAs associated with ARDS. We isolated one miRNA candidate and characterized its role in lipopolysaccharide (LPS)-induced proinflammatory cytokine production in lung macrophages. We further evaluated its functional role in ARDS model by assessing histological change, neutrophil activation, tissue permeability and tumor necrosis factor alpha (TNFα) production. We also characterized its downstream target using luciferase assay, Western blotting, enzyme-linked immunosorbent assay and cell inflammation assay. Results: Microarray profiling revealed miR-802 was significantly downregulated in ARDS mouse model. LPS-induced miR-802 downregulation was confirmed in lung macrophages. Overexpression of miR-802 significantly suppressed LPS-induced inflammatory cytokine production in vitro and alleviates LPS-induced acute lung injury in vivo. Peli2 was identified as a downstream target of miR-802 and found upregulated in ARDS model. Overexpressing Peli2 abolished the antagonizing effect of miR-802 on LPS-mediated inflammatory response. Conclusion: MiR-802 carried a protective role against LPS-induced acute lung injury by downregulating Peli2. MiR-802/Peli2 axis may act as intervening targets to manage ARDS. [ABSTRACT FROM AUTHOR]

Five polysaccharides, namely ADPs-1a, ADPs-1b, ADPs-2, ADPs-3a and ADPs-3b, were extracted from Angelicae dahuricae Radix, purified, and identified by high performance gel permeation chromatography (HPSEC), gas chromatography (GC), Fourier transform infrared (FT-IR) spectrometer and nuclear magnetic resonance spectra (NMR), including the determination of procoagulant activity in vitro. The average molecular weight ( Mw) of the polysaccharides was 153,800, 8312, 111,700, 3766 and 96,680 g/mol, respectively. Coagulation assays indicated that ADPs-1b, ADPs-2, ADPs-3a and ADPs-3b had procoagulant activities. ADPs-1b exerted the procoagulant activities through intrinsic pathway, extrinsic pathway and increased the content of FIB in vitro. ADPs-2 exerted the procoagulant activities through intrinsic pathway and extrinsic pathway. ADPs-3a had procoagulant activities and the activity was associated with the intrinsic pathway and increased the content of FIB. ADPs-3b exerted the activities through extrinsic pathway and increased the content of FIB. [ABSTRACT FROM AUTHOR]

The article offers information on the chemical composition Caragana sinica, a species belonging to the genus Caragana. Among the composition of Caragana include β,-Sitosterol, ursolic acid, and α-amyri. It discussses the use of Caragana as folk medicines for treating vascular hypertension, asthenia syndrome, leukorrhagia, dizziness and tinnitus in China.

Mesenchymal stem cells (MSCs) are heterogeneous likely consisting of subpopulations with various therapeutic potentials. Here we attempted to acquire a subset of MSCs with enhanced effect in wound healing. We found that human placental MSCs expressing platelet-derived growth factor (PDGF) receptor (PDGFR)-β exhibited greater proliferation rates and generated more colony-forming unit-fibroblast (CFU-F), compared to PDGFR-β MSCs. Notably, PDGFR-β MSCs expressed higher levels of pro-angiogenic factors such as Ang1, Ang2, VEGF, bFGF and PDGF. When 10 GFP-expressing MSCs were topically applied into excisional wounds in mice, PDGFR-β MSCs actively incorporated into the wound tissue, resulting in enhanced engraftment (3.92 ± 0.31 × 10 remained in wound by 7 days) and accelerated wound closure; meanwhile, PDGFR-β MSCs tended to remain on the top of the wound bed with significantly fewer cells (2.46 ± 0.26 × 10) engrafted into the wound, suggesting enhanced chemotactic migration and engraftment of PDGFR-β MSCs into the wound. Real-Time PCR and immunostain analyses revealed that the expression of PDGF-B was upregulated after wounding; transwell migration assay showed that PDGFR-β MSCs migrated eightfold more than PDGFR-β MSCs toward PDGF-BB. Intriguingly, PDGFR-β MSC-treated wounds showed significantly enhanced angiogenesis compared to PDGFR-β MSC- or vehicle-treated wounds. Thus, our results indicate that PDGFR-β identifies a subset of MSCs with enhanced chemotactic migration to wound injury and effect in promoting angiogenesis and wound healing, implying a greater therapeutic potential for certain diseases. [ABSTRACT FROM AUTHOR]

Ionic liquid 1-butyl-3-methylimidazolium bromide-methanol-based ultrasonic-assisted extraction (ILUAE) was used to extract tilianin and acacetin from the aerial parts of Agastache rugose ( A. rugose), and simultaneously determined by reversed phase high performance liquid chromatographic (RP-HPLC) method with ultraviolet detection (RP-HPLC-UV). An InertSustain RP-C column was used with the mobile phase consisting of methanol and 0.2% acetic acid as gradient elution at the detection wavelength of 332 nm. The flow rate was 0.8 mL/min, and the column temperature was 30 °C. Under the optimized conditions, tilianin and acacetin displayed good linearity in the ranges of 0.0595-4.76 and 0.0585-4.68 μg/mL, respectively, with the average recoveries being 96.93 and 97.88%, respectively. The method of ILUAE was compared with the traditional methods, it exhibited higher efficiency, higher reproducibility and environmental friendly in analyzing the active compounds in traditional Chinese medicines (TCMs). [ABSTRACT FROM AUTHOR]

From spring to autumn, heavy Microcystis blooms always occur in Lake Taihu, although environmental conditions vary markedly. We speculated that Microcystis genotype succession could play an important role in adaptation to environmental changes and long-term maintenance of the high Microcystis biomass. In this study, we investigated Microcystis genotype succession pattern and the related environmental variables in Lake Taihu during cyanobacterial blooms. Denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction -amplified the genus-specific cpcBA and mcyJ gene fragments was used to monitor the variations of Microcystis genotype and potential microcystin (MC)-producing Microcystis genotype compositions during blooms biweekly in three sites (Meiliang Bay, lake center, and Gonghu Bay) and CANOCO 4.5 for Windows were used for the multivariate statistical analysis of their relationships to environmental variables. DGGE patterns indicated that the number of dominant cpcBA genotype per sample increased from spring to autumn. Principal component analysis ordination plots of DGGE profiles showed clear temporal distribution pattern, but not spatial distribution pattern based on both cpcBA and mcyJ genotype compositions. These results indicated there were relatively gradual successions of Microcystis cpcBA and mcyJ genotype compositions in each site, and no distinct spatial difference among the three sites. Redundancy analyses of the gel patterns showed that, in all the three sites, three environmental factors (nitrate, pH, and chemical oxygen demand) were correlated significantly to successions of both cpcBA and mcyJ genotypes except for mcyJ genotype in the lake center. Spearman's correlations indicated that the three environmental variables were also strongly correlated with chl a and MC concentrations. These results suggested that the environmental factors affecting succession of Microcystis community composition might also influence the growth of Microcystis and MC production. [ABSTRACT FROM AUTHOR]

A thermo-responsive membrane, PVDF-g-PNIPAAm, was successfully prepared from poly(vinylidene fluoride) (PVDF) membrane through surface-initiated atom transfer radical polymerization (ATRP) of a thermo-responsive monomer, N-isopropyl acrylamide (NIPAAm). The effect of the mass ratio of PVDF membrane to NIPAAm monomer on ATRP was studied in detail. The grafting copolymer was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the NIPAAm was successfully grafted on the PVDF membrane, the membrane pores became smaller and the mass ratio 1:8 of PVDF membrane to NIPAAm was in favor of surface-initiated ATRP. The thermal stability of PVDF membrane and PVDF-g-PNIPAAm membranes was characterized by differential scanning calorimetry (DSC). Contact angles of membrane surface, water penetration and protein solution permeation were tested. Water contact angles of PVDF membrane reduced after the surface grafting of NIPAAm, which illuminated that the hydrophilicity of the grafted membrane was improved. The PVDF-g-PNIPAAm membranes exhibited good thermo-responsive permeability and antifouling property. [ABSTRACT FROM AUTHOR]

Background: The flowers of Malus pumila Mill (Rosaceae) is rich in resources, but lack of medicinal value research. Chemical constituents of the same family M. pumila have coagulatory activity. Considering the coagulatory activity could be beneficial for various cardiovascular diseases, the aim of this study is to evaluate coagulatory active constituents of M. pumila flowers.Methods: Chemical constituents of M. pumila flowers were isolated by various column chromatographies, and their coagulatory activity were evaluated by activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (FIB) in vitro.Results: Nine compounds were isolated from M. pumila flowers, and identified as kaempferol-3-O-β-D-glucopyranoside (1), kaempferol-7-O-β-D-glucopyranoside (2), kaempferol-3-O-α-L-arabinofuranoside (3), phloridzin (4), kaempferol (5), phloretin (6), β-sitosterol (7), lupeol (8) and pyracanthoside (9). Compounds 1-9 were isolated from the flowers for the first time, compounds 1, 2 and 9 were isolated from the genus for the first time. Compound 2 could significantly shorten APTT, TT and PT, but significantly decrease the content of FIB. Compound 3 could shorten PT. Compound 4 could significantly shorten TT and PT, but significantly decrease the content of FIB. Compound 5 shortened APTT. Compound 6 and 7 could significantly shorten APTT and PT. Compound 9 was able to prolong TT and decrease the content of FIB, but shorten PT.Conclusions: Compounds 2-7 possessed significant procoagulant activity in vitro, compound 9 had anticoagulant activity in vitro, which showed coagulation potential of compounds from M. pumila flowers, as a new source of bioactive molecules for therapeutic purposes. [ABSTRACT FROM AUTHOR]