Intermediate states and structure evolution in the free-falling process of the dislocation in graphene

<p>This paper investigated the intermediate states and the structure evolution of the dislocation in graphene when it falls freely from the saddle point of the energy landscape. The <i>O</i>-type dislocation, an unstable equilibrium structure located at the saddle point, is obtained from the lattice theory of the dislocation structure and improved by the <i>ab</i> <i>initio</i> calculation to take the buckling into account. Intermediate states along the kinetics path in the falling process are obtained from the <i>ab</i> <i>initio</i> simulation. Once the dislocation falls from the saddle point to the energy valley, this <i>O</i>-type dislocation transforms into the stable structure that is referred to as the <i>B</i>-type dislocation, and in the meantime, it moves a distance that equals half a Burgers vector. The structure evolution and the energy variation in the free-falling process are revealed explicitly. It is observed that rather than smooth change, a platform manifests itself in the energy curve. The unusual behaviour in the energy curve is mainly originated from symmetry breaking and bond formation in the dislocation core. The results can provide deep insight in the mechanism of the brittle feature of covalent materials.</p

Exploring the Dissolution Behavior of <i>m</i>‑Hydroxybenzoic Acid in 14 Pure Solvents Using Thermodynamic, Molecular Simulation and Hansen Solubility Parameters

In this study, the solubility of m-hydroxybenzoic acid in 14 organic pure solvents (acetone, iso-propanol, ethanol, n-propanol, methanol, ethylene glycol, n-pentanol, n-butanol, methyl acetate, n-propyl acetate, ethyl acetate, butyl acetate, iso-propyl acetate, acetonitrile) at the pressure of 0.1 MPa (at T = 278.15–323.15 K) was studied by the static weight method. The order of solubility (molar fraction) of m-hydroxybenzoic acid in the 14 pure solvents at 278.15 K was acetone > iso-propanol > ethanol > n-propanol > methanol > ethylene glycol > n-pentanol > n-butanol > methyl acetate > n-propyl acetate > ethyl acetate > butyl acetate > iso-propyl acetate > acetonitrile. As the temperature improved, the solubility correspondingly increased. The m-hydroxybenzoic acid solubility data in pure solvents were connected using the modified Apelblat model, the λh model, the NRTL model, and the Wilson model, and the best-fit performance was obtained using a modified Apelblat model. Performance was obtained using a modified Apelblat model. Two molecular dynamics analysis methods, Hirshfeld surface analysis and molecular electrostatic potential surface (MEP) analysis, were used to determine the dissolution process of m-hydroxybenzoic acid crystals and the interaction sites with solvent molecules in solution. The Hansen solubility parameters (HSPs) were utilized to assess the solvent’s capability and to elucidate its ability to dissolve m-hydroxybenzoic acid

Configuring Effectively Double Temperature Difference Control Schemes for Distillation Columns

The conventional method for configuring double temperature difference control (DTDC) schemes relies on sensitivity analysis (SA) and singular value decomposition (SVD) analysis, respectively, to determine sensitive and reference stages. Since no considerations are given at all to the interactions between the synthesized double temperature differences (DTDs) and to the coordination between the upper and lower temperature differences (TDs) subtracted in each synthesized DTD, the conventional method may lead to DTDC schemes that fail to secure tight product quality control of distillation columns. In this article, a novel method is proposed that employs a newly defined metric in our recent work, the averaged absolute variation magnitudes (ASVM), to determine the two reference stages in each DTDC loop. The ASVM measures the variations of TDs between the sensitive stage and the remaining ones with the assumption of complete rejection of all disturbances concerned and can thus reflect the inherent characteristics of coupling between the controlled product qualities. For each DTDC loop, while the first reference stage should be chosen to cope with its coupling with the other control loops, the second reference stage should be to coordinate the two TDs involved, thereby yielding a favorable effect to the inference of the controlled product qualities. Four example systems, including one conventional distillation column separating a binary mixture of ethanol and butanol, two conventional distillation columns separating a ternary mixture of ethanol, propanol, and butanol, and one dividing-wall distillation column separating a ternary mixture of ethanol, propanol, and butanol, are used to assess the proposed method by means of in-depth comparison with the conventional method. While they display comparable dynamic performances, the former leads to considerably smaller steady-state deviations in the controlled product qualities than the latter. These striking outcomes demonstrate evidently that the proposed method can be a promising alternative for the pursuit of tight temperature inferential control of various distillation columns

Additional file 1 of Chemotherapy and targeted therapy for advanced biliary tract cancers: an umbrella review

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Additional file 3 of Chemotherapy and targeted therapy for advanced biliary tract cancers: an umbrella review

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Additional file 4 of Chemotherapy and targeted therapy for advanced biliary tract cancers: an umbrella review

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The regulatory element containing the TT>A variants demonstrates enhancer activity.

<p>Sequences carrying risk (-A) and non-risk (TT) polymorphisms were cloned upstream of a minimal thymidine kinase promoter luciferase construct to measure luciferase activation following transient transfection and stimulation. a. HEK293T cells stimulated with P/I for 48 hours. b. THP1 cells stimulated with LPS for 48 hrs. c. THP1 cells stimulated with P/I for 48 hours. Statistical comparisons were performed using a Student's <i>t</i>-test of three biological independent experiments, * indicates p<0.05.</p

The Transformation of Two-Line Ferrihydrite into Crystalline Products: Effect of pH and Media (Sulfate versus Nitrate)

Two-line ferrihydrite (Fh), ubiquitous in soils, groundwater, and aquatic sediments, may serve as an important sink for sequestering trace metals, metalloids, and organic matter via adsorption/coprecipitation due to its high surface area and reactivity. Although considerable attention has been paid to the transformation process of this thermodynamically metastable solid, little is known about the transformation products, the crystallization rates, or the transformation routes of two-line Fh in sulfate- and calcium-rich environments. This work systematically investigates the transformation of 2-line ferrihydrite produced by using different neutralization reagents (CaO vs NaOH) at different pHs (4 and 8), temperatures (25 °C, 40 °C, and 80 °C), and media (sulfate vs nitrate). X-ray diffraction, Raman, Fourier transform infrared spectroscopy, and chemical extraction were employed to characterize the transformed solids as well as the crystallization rate of 2-line Fh. The results show that the crystallization products in nitrate media include hematite (major) and goethite (minor) under acidic conditions (pH 4) and only hematite under alkaline conditions (pH 8) and are independent of the neutralization reagent used. By contrast, in sulfate media, goethite is the dominant product under slightly acidic conditions (pH 4) with 6-line ferrihydrite as the intermediate product, whereas under slightly alkaline conditions the formation of hematite is favored. Chemical extraction results indicate that the transformation process of those CaO-neutralized solids precipitated at pH 8 is intensely retarded by calcium ion. The results suggest that neutralization reagents (calcium ion), as well as the reaction media (sulfate ion), play an important role in the 2-line ferrihydrite crystallization process

3C analysis demonstrates long-distance interactions between the TT>A enhancer and the <i>TNFAIP3</i> gene region.

<p>a. The track on the top is the location of the <i>TNFAIP3</i> primers used to identify potential amplified interaction fragments tested by 3C. Primers 6–10, 16 and 24 produced signals and are marked with asterisks. The middle and bottom track shows the genomic region of <i>TNFAIP3</i> with the location of the promoter CpG island and ENCODE defined transcription factor binding sites. b. Increased relative interaction frequencies (RCF) were detected in three regions of <i>TNFAIP3</i>, the promoter, intron 2 and the 3′ untranslated region. c. Stimulation of THP1 cells with LPS results in increased 3C interactions between the TT>A enhancer and the <i>TNFAIP3</i> promoter along with a concomitant increase in A20 expression and IκBα phosphorylation. Shown is a representative blot from 3 independent experiments. Statistical differences were determined using Student's <i>t</i>-test.</p

SATB1 is required for the TT>A enhancer-promoter interaction and <i>TNFAIP3</i> transcription.

<p>a. Shown is a representative 3C assay from 3 independent experiments in HEK293T cells. Relative crosslinking frequencies (RCF) were normalized to both <i>GAPDH</i> loading control and a <i>TNFAIP3</i> BAC clone and plotted according to its location to <i>TNFAIP3</i> gene and the TT>A enhancer. High local interaction frequencies near the TT>A enhancer serve as a positive control (fragments 30–34). b. The top panel shows the protein expression levels of SATB1 and A20 were detected using Western blots with antibodies against SATB1 and A20, respectively. β-actin was used as loading control. The bottom two panels show densitometer quantification of the relative expression of SATB1 (middle panel) and A20 (lower panel) normalized to β-actin. Error bars represent standard error of the mean from 3 independent experiments. Differential protein levels between SATB1 knockdown and non-silencing shRNA control were calculated using Student's <i>t</i>-test.</p