The ultra-high voltage direct current (UHVDC) converter station is the core of the UHVDC project to realize the mutual conversion of alternating current (AC) and direct current (DC). Its operational ...reliability directly affects the safety of personnel and equipment and the stable operation of the grid. The firestop system is key part of the protective system in converter station, and it faces the threat of fire and explosion of converter transformer. In this paper, in order to analyze the shortcomings of the existing firestop system of valve halls, numerical models for fire and blast resistance analysis of typical firestop system are established. For a typical UHVDC converter station, the temperature distribution under hydrocarbon heating curve and dynamic response under different blast loads are analyzed by using the established numerical model. And the results show that the existing firestop system has good heat insulation performance, while the blast resistance cannot meet the demand.
In this work, we prepared ZnGeP
2
(ZGP) photocatalyst using single flat temperature zone (SFT) method in a vacuum quartz ampoule. The XRD, SEM, EDS, DRS and XPS were used to characterize the crystal ...structure, morphology, elemental content, optical absorption and band gap structure of ZGP. The results of photocatalytic hydrogen evolution and apparent quantum efficiency show that ZGP is a promising photocatalyst for hydrogen production both under visible and near-infrared light irradiation. In addition, it is also found that adding the common stabilizer H3PO2 and ultrasonic treatment can efficiently improve the photocatalytic activity and stability of ZGP.
Chromosomal translocations generating fusion proteins are frequently found in human leukemias. The fusion proteins play an important role in leukemogenesis by subverting the function of one or both ...partner proteins. The leukemogenic CALM-AF10 fusion protein is capable of interacting with the histone H3 lysine 79 (H3K79)–specific methyltransferase hDOT1L through the fused AF10 moiety. This interaction leads to local H3K79 hypermethylation on Hoxa5 loci, which up-regulates the expression of Hoxa5 and contributes to leukemogenesis. However, the long latency of leukemogenesis of CALM-AF10 transgenic mice suggests that the direct effects of fusion oncogene are not sufficient for the induction of leukemia. In this study, we show that the CALM-AF10 fusion protein can also greatly reduce global H3K79 methylation in both human and murine leukemic cells by disrupting the AF10-mediated association of hDOT1L with chromatin. Cells with reduced H3K79 methylation are more sensitive to γ-irradiation and display increased chromosomal instability. Consistently, leukemia patients harboring CALM-AF10 fusion have more secondary chromosomal aberrations. These findings suggest that chromosomal instability associated with global epigenetic alteration contributes to malignant transformation in certain leukemias, and that leukemias with this type of epigenetic alteration might benefit from treatment regimens containing DNA-damaging agents. This study is registered with www.clinicaltrials.gov as NCT00266136.
Ligament tissue engineering is currently a novel approach to the treatment of ligament injury, which can replace the deficiency of autografts. Ligament tissue engineering consists of four basic ...elements:seed cells, nanoscaffolds, growth factors, and mechanical stimulation. At present, the main problem in ligament tissue engineering is how to control seed cells to ligament cells more controllly. The study found that each physical property of the natural bio ligament and mechanical stimulation (uniaxial stretching) plays an important role in the differentiation of stem cells into ligament cells. Therefore, the design of nanofiber scaffolds must consider the elastic modulus of the material and the material. Structure(material arrangement, porosity and diameter, etc.), elastic modulus and material structure in different ranges will guide cells to differentiate into different lineages. Considering that the ligament is the main force-bearing tissue of the human body, mechanical stimulation is also essential for ste
A new three‐dimensional interpenetrated CdII–organic framework based on 3,3′‐azodibenzoic acid 3,3′‐(diazenediyl)dibenzoic acid, H2azdc and the auxiliary flexible ligand ...1,4‐bis(1H‐imidazol‐1‐yl)butane (bimb), namely polybisμ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′μ2‐3,3′‐(diazenediyl)dibenzoato‐κ2O:O′cadmium(II) monohydrate, {Cd(C14H8N2O4)(C10H14N2)2·H2O}n, (1), was obtained by a typical solution reaction in mixed solvents (water and N,N′‐dimethylformamide). Each CdII centre is six‐coordinated by two O atoms of bis‐monodentate bridging carboxylate groups from two azdc2− ligands and by four N atoms from four bimb ligands, forming an octahedral coordination environment. The CdII ions are connected by the bimb ligands, resulting in two‐dimensional (4,4) layers, which are further pillared by the azdc2− ligands, affording a threefold interpenetrated three‐dimensional α‐Po topological framework with the Schläfli symbol 41263. The thermal stability and solid‐state fluorescence properties of (1) have been investigated.
Background and Aims Animal experiments showed that interaction between advanced glycation end products (AGE) and their receptors (RAGE) play an important role in the pathogenesis of diabetic ...complications. Soluble RAGE (sRAGE) can function as a decoy for RAGE ligands. The present study aimed to examine the levels of AGEs, RAGE and sRAGE in patients with type 2 diabetes (T2D). Methods RAGE gene expression was determined by real-time PCR in 50 patients with T2D (27 men, mean age 52 ± 7.7 years) and 50 age-matched controls without T2D. Serum AGEs and sRAGEs were assayed by enzyme-linked immunosorbent assay (ELISA). Results Serum level of AGEs was increased in patients with T2D (10.35 ± 2.27 μg/mL vs.7.69 ± 0.56 μg/mL, p <0.05). sRAGE was decreased in patients with T2D (573.6 ± 172.5 pg/mL vs. 603.4 ± 120.8 pg/mL p <0.01). RAGE gene expression was higher in T2D than in controls ( p <0.01). There was an association between monocyte RAGE and serum levels of AGEs in both T2D patients ( r = 0.29, p = 0.03) and controls ( r = 0.31, p = 0.02). Serum AGEs correlated with homeostasis model assessment of insulin resistance (HOMA-IR) in both patients with T2D (r = 0.322, p = 0.004) and controls (r = 0.281, p = 0.003). Conclusions Serum AGEs and monocyte RAGE expression are increased in patients with T2D, whereas serum sRAGE is decreased. Pharmacological intervention on serum AGEs and sRAGE may be a potential therapy for diabetes.
Reactions of 3,3′-azodibenzoic acid (H
2
azdc) with Mn(II) and Cd(II) in the presence of 1,10-phenanthroline (phen) yield two new metal-organic coordination polymers, {Mn(azdc)(phen)(DMF)(H
2
O)}
n
...(1) and {Cd(azdc)(phen)}
n
(2), which display 1-D azdc-bridged coordination arrays with different topology. 1 was synthesized under ambient conditions and exhibits a zigzag chain structure, further extending into a 2-D supramolecular double layer through C-H
π and C-H
O hydrogen bonds. Solvothermally 2 was obtained and shows a double-chain structure. Adjacent double chains are linked by C-H
N hydrogen bonds to give a 2-D supramolecular wavy double layer. Distinct extended 3-D supramolecular network architectures are further constructed with weak secondary interactions, especially aromatic stacking and hydrogen bonding as supramolecular driving forces. The coordination modes of azdc
2−
and crystalline architectures of the complexes depend on the central metal ions. The desolvation-resolvation behavior of 1 has been explored. Thermal stabilities of 1 and 2 have been studied. Solid-state fluorescence of 2 has been investigated.
Cu-Al/Al nanostructured metallic multilayers with Al layer thickness hAl varying from 5 to 100 nm were prepared, and their mechanical properties and deformation behaviors were studied by ...nanoindentation testing. The results showed that the hardness increased drastically with decreasing hAl down to about 20 nm, whereafter the hardness reached a plateau that approaches the hardness of the alloyed Cu-Al monolithic thin films. The strain rate sensitivity （SRS, m）, however, decreased monotonically with reducing hAl. The layer thickness-dependent strengthening mechanisms were discussed, and it was revealed that the alloyed Cu-Al nanolayers dominated at hAl≤ 20 nm, while the crystalline Al nanolayers dominated at hAl 〉 20 nm. The plastic deformation was mainly related to the ductile Al nanolayers, which was responsible for the monotonic evolution of SRS with hAl. In addition, the hAFdependent hardness and SRS were quanti- tatively modeled in light of the strengthening mechanisms at different length scales.
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