Compared with experimental studies on reinforced concrete joints subjected to monotonic loading under progressive collapse, numerical predictions are much more economic, convenient and efficient. As ...a general-purpose finite element program, ABAQUS can be employed to simulate the deformation and failure behaviour of RC beam-column joints. When simulating different types of two dimensional beam-column joints, namely knee, exterior and interior joints, it should be noted that the accuracy of the material properties in the numerical models, especially for concrete, are crucial to the accuracy and the reliability of predictions. Therefore, in this study, appropriate specimens subjected to monotonic loading are selected from several series of experimental studies and simulated in ABAQUS. By comparing the predictions with corresponding experimental results, the required material parameters in ABAQUS are calibrated to provide a reference for future RC joint simulations of progressive collapse.
Abstract
Scratch resistant surface of polypropylene (PP) is of critical importance for automobile, household appliances and other industries. In this paper, the mechanical and scratch properties of ...PP were studied by incorporation of three types of inorganic particles, including graphene (GP), silicon dioxide (SiO
2
) and zeolite powder (ZP), respectively. Maleic anhydride grafted polypropylene was used as compatibilizer. The effects of inorganic particle content on crystallization, mechanical properties and scratch resistance of PP composites were studied. Results showed that adding inorganic fillers led to enhanced crystallinity of PP, thus improving the scratch resistance of PP materials. Compared with PP/SiO
2
and PP/ ZP, PP/GP exhibited the best scratch resistance and low sensitivity to scratch deformation at 2 wt% filler. We believe that the scratch resistance of PP was determined by material characteristics and crystallinity. This will be a reference for the research on the scratch resistance of other polymer materials.
The cyclic deformation characteristics and fatigue behaviors of Hadfield manganese steel have been investigated by means of its ability to memorize strain and stress history. Detailed studies were ...performed on the strain-controlled low cycle fatigue (LCF) and stress-controlled high cycle fatigue (HCF). Initial cyclic hardening to saturation or peak stress followed by softening to fracture occurred in LCF. Internal stress made the dominant contribution to the fatigue crack propagation until failure. Effective stress evolution revealed the existence of C–Mn clusters with short-range ordering in Hadfield manganese steel and demonstrated that the interaction between C atoms in the C–Mn cluster and dislocation was essential for its cyclic hardening. The developing/developed dislocation cells and stacking faults were the main cyclic deformation microstructures on the fractured sample surface in LCF and HCF, which manifested that fatigue failure behavior of Hadfield manganese steel was induced by plastic deformation during strain-controlled or stress-controlled testing.
The Chinese Altai is a typical part of the Central Asian Orogenic Belt (CAOB), but its tectonic evolution is not well understood. Geochemical study of Early Paleozoic metasedimentary rocks was ...conducted to better constrain their provenance and tectonic environment. These rocks have relatively low CIA values (49 to 79), with ICV values (0.73–1.36) higher than that of post-Archean Australian average shale (PAAS), suggesting that they experienced relatively weak chemical weathering and were mainly derived from an immature source. Compared to PAAS and upper crust, the samples mostly have relatively lower high field strength elements (HFSE) (e.g. Zr, Hf, Nb, Ta) and large ion lithophile element (LILE) contents (e.g. Rb, Sr, Ba, Th, U, Pb). However, their relatively high Rb concentrations (>
40 ppm), low Rb/Sr (0.04–3.24) and Th/U (Th/U
=
3–8) ratios are indicative of an acidic-intermediate igneous source that had undergone weak chemical weathering. All of the samples are moderately enriched in LREE (light REE) and show relatively flat Chondrite-normalized HREE (heavy REE) patterns (La
N/Yb
N
=
3.2–12.6) with various negative Eu anomalies (Eu/Eu⁎
=
0.4–0.9). Meta-arenaceous samples have moderate SiO
2 (average 72.9 wt.%), Al
2O
3 (average 11.5 wt.%), Fe
2O
3
T
+
MgO (average 7.16 wt.%) contents and moderate Al
2O
3/SiO
2 (average 0.16), K
2O/Na
2O (average 0.93) ratios, similar to those of graywackes from continental island arcs or active continental margins. However, meta-argillaceous samples have high SiO
2 (average 60.8 wt.%), Al
2O
3 (average 17.2 wt.%), Fe
2O
3
T
+
MgO (average 12.2 wt.%) contents and high K
2O/Na
2O (average 3.45), Al
2O
3/SiO
2 (average 0.28) ratios similar to mudstones from continental arc basins. This kind of tectonic environment is also manifested in tectonic discrimination diagrams including Th–Sc–Zr/10 and La–Th–Sc. These geochemical characteristics suggest that the metasedimentary rocks were deposited in an active continental margin or continental arc setting. This does not favor the previously proposed passive continental margin model. Therefore, this study supports an arc accretion model for the Chinese Altai.
The p–c–T curves of tritium absorption and desorption of titanium were measured using the method of step equilibrium by stepping up the tritium quantity on an experimental apparatus of metal hydride. ...The p–c–T curves for tritium have one plateau at temperature below 300°C and two plateaus at temperature above 300°C. The thermodynamic parameters of the different phases were determined according to the van’t Hoff equation. The hysteresis effect was not observed in reversible process of tritium absorption and desorption of titanium on our experimental condition. The tritium absorption behavior of titanium in the temperature ranging from 550°C to 750°C and desorption behavior of titanium in the temperature ranging from 350°C to 550°C have been investigated in a constant volume system. A method of the reaction rate analysis was proposed and examined for determining the rate constant. The apparent activation energy obtained by this analysis for the absorption and the desorption were 155.5 ± 3.2 kJ mol−1 and 62.1 ± 1.6 kJ mol−1 respectively.
ABC294640 is a non-lipid competitive inhibitor of SphK2. It exhibited anti-proliferative activities in many human malignancies, including ovarian cancer. However, its potential mechanism of action ...remains poorly understood.
In this paper, epithelial ovarian cancer (EOC) cell lines SKOV3 and HO8910 were treated with ABC294640. In order to explore the effect of ABC294640 on the behavior of ovarian cancer cells in vitro, we used cell counting kit-8 (CCK-8) assays, colony formation assays, flow cytometry, quantitative real-time PCR (qRT-PCR), Western blot analysis and immunohistochemistry to detect the effect of ABC294640 on cell proliferation, cell cycle distribution, cell apoptosis, the expression of related factors at mRNA levels, and the expression of related factors at protein level. An intra-abdominal xenograft tumor model of EOC was set up to assess the tumor growth in nude mice.
The results obtained indicate that EOC cell proliferation was noticeably inhibited in a concentration-dependent manner by ABC294640. ABC294640 caused cell cycle arrest in S phase and increased cell apoptosis rate in EOC cells. Also, the proteins, including phosphorylated retinoblastoma protein (
Rb), cyclin D1, cyclin B1, and Bcl-2 were significantly inhibited, while cleaved-caspase 3 was activated. ABC294640 inhibited the expression of c-Myc in EOC. The in vivo assay showed an inhibitory effect of ABC294640 on tumor growth.
ABC294640 could downregulate the expression of c-Myc in EOC both in vitro and in vivo. ABC294640 inhibited tumor growth in EOC via cell cycle arrest and inducing cell apoptosis both in vitro and in vivo, partially by decreasing the expression of cell cycle-associated proteins (such as
-Rb, cyclin B1, and cyclin D1) and promoting caspase 3 activation via downregulation expression of c-Myc. It suggested that ABC294640 had the potential to serve as an agent in EOC treatment.
In the present study, two new cyclic bisbibenzyls (1, 2) co-occuring with a known compound, isoplagiochins C (3) were isolated from Hebertus dicranus. The structures were determined mainly by ...extensive 1D and 2D NMR experiments, and the absolute configurations of 1 and 2 were established by the circular dichroism spectrum. Furthermore, all these three rare compounds were tested in vitro for inhibitory activity against the growth of human cancer cell lines (A549, HCT116, MDA-MB-231, and BEL7404) by the MTT assay, and compound 2 exhibited moderately inhibitory activity with IC50 values ranging from 13.89 to 31.62 μmol·L−1. In conclusion, our results provided a basis for future development and modification of these compounds for cancer therapy.
Objective: To explore the correlation of bone marrow polychonal plasma cell proportion (pPC% ) and clinical features in newly diagnosed multiple myeloma (NDMM) patients. Methods: A retrospective ...analysis of 317 patients with NDMM admitted to Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2018 to January 2023 was performed. The results of the pPC% in all patients were clear. The relationship between the pPC% and clinical characteristics was analyzed. Results: A total of 317 patients were included, comprising 180 males and 137 females. The median age at diagnosis was 61 (26-91) years, and 55.8% were 60 years or older. The pPC% in the bone marrow of patients with NDMM was different in the DS, International Staging System (ISS), and revised ISS (R-ISS) stages (P=0.002, 0.010, and 0.049, respectively), whereas no statistical difference in pPC% was observed among patients with different FISH risk stratigrams (P=0.971). The correlation coefficient between pPC% and
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