Inversion using a new low-dimensional representation of complex binary geological media based on a deep neural network

Efficient and high-fidelity prior sampling and inversion for complex geological media is still a largely unsolved challenge. Here, we use a deep neural network of the variational autoencoder type to construct a parametric low-dimensional base model parameterization of complex binary geological media. For inversion purposes, it has the attractive feature that random draws from an uncorrelated standard normal distribution yield model realizations with spatial characteristics that are in agreement with the training set. In comparison with the most commonly used parametric representations in probabilistic inversion, we find that our dimensionality reduction (DR) approach outperforms principle component analysis (PCA), optimization-PCA (OPCA) and discrete cosine transform (DCT) DR techniques for unconditional geostatistical simulation of a channelized prior model. For the considered examples, important compression ratios (200 - 500) are achieved. Given that the construction of our parameterization requires a training set of several tens of thousands of prior model realizations, our DR approach is more suited for probabilistic (or deterministic) inversion than for unconditional (or point-conditioned) geostatistical simulation. Probabilistic inversions of 2D steady-state and 3D transient hydraulic tomography data are used to demonstrate the DR-based inversion. For the 2D case study, the performance is superior compared to current state-of-the-art multiple-point statistics inversion by sequential geostatistical resampling (SGR). Inversion results for the 3D application are also encouraging

On the mechanism of pressure rise in vented explosions: A numerical study

Accidental gas explosions are a significant concern in process industries. In an explosion event, the promotion of flame acceleration due to turbulence generated from obstacles is responsible for many severe damages. This paper discusses the numerical evaluation and the mechanism of pressure rise in vented explosions in the presence of obstructions using computational fluid dynamics (CFD). The large eddy simulation (LES) technique is employed with a dynamic flame surface density (DFSD) in the combustion model to account for the filtered chemical source term. The experimental test case considered for the validation of simulations is a small-scale explosion chamber with removable baffle plates and obstacles. It is found that the maximum overpressure increases with the baffle plates moved downstream from the ignition source or when additional baffles are placed in sequence. Large separation between baffles and the central obstacle results in lower overpressure due to the relaminarisation of the flame front. The trend of explosion overpressure is related to the competition between the strength of venting and expansion in the explosion chamber. Extensive interactions between the flame and the obstruction-generated turbulence are found to wrinkle the flame front and increase the burning rate. Satisfactory agreements have been obtained between LES and the experimental data. This confirms the capability of the developed model in predicting essential safety-related parameters in vented explosions. Results reveal the potential of using LES in the selection of design aspects for loss prevention, such as the area of vents and distance between congested regions in chemical processing plants

Corresponding hairpin templates for siRNA target sites. Portions of the target sequences are underlined.

<p>Corresponding hairpin templates for siRNA target sites. Portions of the target sequences are underlined.</p

miRNA126, VEGFC and BCL-2 levels in RAECs and ARAECs.

<p>Cells were cultured under normal conditions and miRNA126, VEGFC, and BCL-2 levels were assessed with quantitative PCR and specific antibodies against VEGF and BCL-2, respectively. (A) Relative miRNA126 levels in RAECs and ARAECs. (B) Representative immunoblots of VEGFC and BCL-2 and corresponding data of optical densities. (C) Mature miRNA126 levels in the supernatants of RAECs and ARAECs. (D) VEGF concentrations in the supernatants of RAECs and ARAECs. Results are the means ± SD of at least 3 separate experiments. **, p<0.01, when compared to the corresponding RAEC group.</p

Apoptotic and proliferation profiles of RAECs and ARAECs.

<p>RAECs and ARAECs were cultured overnight and treated with or without 50 μg/mL of OX-LDL for 48 hours and then were subjected to apoptosis detection by an Annexin V:FITC Apoptosis Detection Kit II (BD). (A) Representative flow cytometry plots. (B) Quantitative measurements of flow cytometric determination of apoptotic cells. (C) Caspase3 activity assay of RAECs and ARAECs. (D) Proliferative curves of RAECs and ARAECs under normal conditions. Results are the means ± SD of at least 3 separate experiments. *, p<0.05 and **, p<0.01, when compared to the corresponding RAEC group or the indicated group.</p

Detection of Lv-Pro-miRNA126 expression over time.

<p>(A, B) RAECs and ARAECs were infected with Lv-Pro-miRNA126, cultured for indicated times and miRNA126 RNA, VEGF and BCL-2 protein levels were assessed by quantitative PCR and western blotting, respectively. (C, D) Uninfected RAECs and ARAECs or ARAECs infected with Lv-Pro-miRNA126 or Lv-shRNA-BCL-2 were treated with or without OX-LDL for 48 hours and subject to an apoptotic assay. Representative plots are shown. Data are the means ± SD of at least 3 separate experiments. **, p<0.01, when compared to the RAECs group or the indicated group.</p

Regioselective Chain Shuttling Polymerization of Isoprene: An Approach To Access New Materials from Single Monomer

Chain shuttling polymerization (CSP) has exhibited unique privilege to combine monomer sequences of different properties into one macromolecular chain, which, however, is difficult to achieve because of low chain transfer efficiency and thus lead to poor architecture control over the resulting polymers. Herein, we reported that the pyridyl–methylene fluorenyl scandium complex <b>1</b> in combination with [Ph₃C]­[B­(C₆F₅)₄] and Al^<i>i</i>Bu₃ showed a high transfer efficiency (93.8%) in the presence of 10 equiv of Al^<i>i</i>Bu₃ toward the chain-transfer polymerization (CTP) of isoprene (IP) in high 1,4-selectivity (83%). Meanwhile, under the same conditions, the analogous lutetium precursor <b>3</b> based system was 3,4-regioselective and exhibited almost perfect chain transfer efficiency (96.5–100%) in a wide range of Al^<i>i</i>Bu₃-to-Lu ratios from 10:1 to 100:1, indicating that each Lu generated apparently 100 polyisoprene (PIP) macromolecules. Both CTPs performed fluently without compromising the selectivity and the activity and had comparable chain transfer rate constants. Based on this, 1,4- and 3,4-regioselective CSPs were realized by mixing <b>1</b> and <b>3</b> in various ratios to give a series of PIPs bearing different distribution of 1,4- and 3,4-PIP sequences and <i>T</i>_g values. This work provides a new strategy to access stereoregular and architecture controlled polymers from a single monomer

Effects of miRNA126 on inflammation-related factors and the MAPK pathway in apoptosis-resistant endothelial cells.

<p>Uninfected RAECs and ARAECs or ARAECs infected with Lv-Pro-miRNA126 or Lv-shRNA-BCL-2 were treated with or without OX-LDL for 48 hours and MAPK pathway related proteins and inflammation-related factors were detected by western blotting. Representative immunoblots and data representing the means ± SD of at least 3 separate experiments are shown. **, p<0.01, when compared to the indicated group.</p

AP1 is involved in the regulation of BCL-2 by miRNA126.

<p>(A, B) RAECSs were infected with or without the indicated lentivirus and miRNA126 and BCL-2 levels were analyzed 72 hours later by quantitative PCR and western blotting, respectively. (C, D) RAECSs were infected with or without the indicated lentivirus and BCL-2 and VEGF were analyzed by western blotting 72 hours later. (E) Representative photo of GFP expression in RAECs infected with Lv-miRNA126 for gene delivery efficiency assessment 72 hours after infection. Results are the means ± SD of at least 3 separate experiments. **, p<0.01, when compared to the corresponding Lv-control group or indicated group.</p

RNA-Seq-Based Analysis of Cold Shock Response in <i>Thermoanaerobacter tengcongensis</i>, a Bacterium Harboring a Single Cold Shock Protein Encoding Gene

<div><p>Background</p><p>Although cold shock responses and the roles of cold shock proteins in microorganisms containing multiple cold shock protein genes have been well characterized, related studies on bacteria possessing a single cold shock protein gene have not been reported. <i>Thermoanaerobacter tengcongensis</i> MB4, a thermophile harboring only one known cold shock protein gene (<i>TtescpC</i>), can survive from 50° to 80°C, but has poor natural competence under cold shock at 50°C. We therefore examined cold shock responses and their effect on natural competence in this bacterium.</p><p>Results</p><p>The transcriptomes of <i>T. tengcongensis</i> before and after cold shock were analyzed by RNA-seq and over 1200 differentially expressed genes were successfully identified. These genes were involved in a wide range of biological processes, including modulation of DNA replication, recombination, and repair; energy metabolism; production of cold shock protein; synthesis of branched amino acids and branched-chain fatty acids; and sporulation. RNA-seq analysis also suggested that <i>T. tengcongensis</i> initiates cell wall and membrane remodeling processes, flagellar assembly, and sporulation in response to low temperature. Expression profiles of <i>TtecspC</i> and failed attempts to produce a <i>TtecspC</i> knockout strain confirmed the essential role of <i>Tte</i>CspC in the cold shock response, and also suggested a role of this protein in survival at optimum growth temperature. Repression of genes encoding ComEA and ComEC and low energy metabolism levels in cold-shocked cells are the likely basis of poor natural competence at low temperature.</p><p>Conclusion</p><p>Our study demonstrated changes in global gene expression under cold shock and identified several candidate genes related to cold shock in <i>T. tengcongensis</i>. At the same time, the relationship between cold shock response and poor natural competence at low temperature was preliminarily elucidated. These findings provide a foundation for future studies on genetic and molecular mechanisms associated with cold shock and acclimation at low temperature.</p></div