30 research outputs found
Endogenous and exogenous galectin-3 promote the adhesion of tumor cells with low expression of MUC1 to HUVECs through upregulation of N-cadherin and CD44
Tumor cell-endothelial adhesion is one of the key steps in tumor cell haematogenous dissemination in metastasis and was previously shown to be mediated by interaction of galectin-3 with the transmembrane mucin protein MUC1. In this study, the effect of exogenous as well as endogenous galectin-3 on adhesion of two cell lines (low MUC1-expressing human prostate cancer PC-3M cells and non-small-cell lung cancer A549 cells) to monolayer of umbilical vein endothelial cells (HUVECs) was investigated. We found that suppression of endogenous galectin-3 expression reduced tumor cell adhesion to HUVECs and also decreased cell invasion and migration. Exogenous galectin-3 promoted tumor cell adhesion to HUVECs by entering cells. Both exogenous and endogenous galectin-3 upregulated the expression of β-catenin and increased β-catenin nuclear accumulation, and subsequently upregulated the expression of N-cadherin and CD44. We deduced that both exogenous as well as endogenous galectin-3 promoted low MUC1-expressing cancer cell adhesion to HUVECs by increasing the expression of N-cadherin and CD44 via an increase of nuclear β-catenin accumulation. These results were confirmed further by using a β-catenin/TCF transcriptional activity inhibitor, N-cadherin or CD44 siRNAs. Taken together, our results suggest a new molecular mechanism of galectin-3-mediated cell adhesion in cancer metastasis
Research on the influence of design parameters on mechanical performance of net arch bridge
In order to study the suspender layout parameters and design parameters of the tied arch bridge with mesh suspenders under the action of vehicle load, the structure stress is more reasonable and meets the higher economy and aesthetics. Taking a 96m span reticulated tied arch bridge as the engineering background, the finite element model is established by using Midas/Civil 2019 program. The variation law of internal force and Suspender Force of the structure is calculated and analysed under the change of rise span ratio and suspender number parameters, and the relatively optimal value range of corresponding parameters is given. The results show that the rise span ratio should be 0.2-0.24; The number of Suspenders for one side arch rib should be 34-38; The relatively optimal range of the above parameters is discussed for reference
Network Patterns of Zhongyuan Urban Agglomeration in China Based on Baidu Migration Data
As a new product of the Internet and big data era, migration data are of great significance for the revealing of the complex dynamic network patterns of urban agglomerations and for studying the relations between cities by using the “space of flows” model. Based on Baidu migration data of one week in 2021, this paper constructs a 30 × 30 rational data matrix for cities in Zhongyuan Urban Agglomeration and depicts the network pattern from static and dynamic perspectives by using social network analysis and dynamic network visualization. The results show that the network of Zhongyuan Urban Agglomeration is characterized by a circular structure with Zhengzhou as the center, a city belt around Zhengzhou as the connection, subcentral cities as the support and peripheral cities as the extension. Zhengzhou is the core city of the entire network, related to which the central and backbone networks divided in this paper account for nearly 40% of the total migration. Shangqiu, Luoyang, Zhoukou and Handan also play an important role in the structure of the migration network as subcentral cities. For a single city, the migration scale generally peaks on weekends and reaches its minimum during Tuesday to Thursday. Regarding the relations between cities, the migration variation can be divided into four types: peaking on Monday, peaking on weekends, bimodal and stable, and there are obvious phenomena of weekly commuting. In general, the links between cities outside Henan Province and other cities in the urban agglomeration are relatively weak, and the constraints of administrative regionalization on intercity migration are presumed to still exist. According to the results, the location advantage for multi-layer development and construction of Zhongyuan Urban Agglomeration should be made use of. In addition, the status as the core city and the radiation range should be strengthened, and the connections between the peripheral cities and the other cities should be improved, so as to promote the integrated and efficient development of the whole urban agglomeration
A novel quorum sensing regulator LuxT contributes to the virulence of Vibrio cholerae
ABSTRACTVibrio cholerae is a waterborne bacterium that primarily infects the human intestine and causes cholera fatality. Quorum sensing (QS) negatively regulates the expression of V. cholerae virulence gene. However, the primary associated mechanisms remain undetermined. This investigation identified a new QS regulator from the TetR family, LuxT, which increases V. cholerae virulence by directly inhibiting hapR expression. HapR is a master QS regulator that suppresses virulence cascade expression. The expression of luxT increased 4.8-fold in the small intestine of infant mice than in Luria-Bertani broth. ΔluxT mutant strain revealed a substantial defect in the colonizing ability of the small intestines. At low cell densities, the expression level of hapR was upregulated by luxT deletion, suggesting that LuxT can suppress hapR transcription. The electrophoretic mobility shift analysis revealed that LuxT directly binds to the hapR promoter region. Furthermore, luxT expression was upregulated by the two-component system ArcB/ArcA, which responses to changes in oxygen levels in response to the host’s small intestine’s anaerobic signals. In conclusion, this research reveals a novel cell density-mediated virulence regulation pathway and contributes to understanding the complex association between V. cholerae virulence and QS signals. This evidence furnishes new insights for future studies on cholerae’s pathogenic mechanisms
New J. Chem.
The photocatalytic hydrogen (H-2) evolution with transition-metal substituted Keggin-type titanium tungstates Na-5(6)[MTiW11O39]center dot xH(2)O (abbreviated as TiW11M (M = Fe, Co, Zn)) as photocatalyst was reported. They showed good photocatalytic activities toward H-2 evolution in homogeneous systems under simulated solar light irradiation. The order of photocatalytic activity was TiW11Co approximate to TiW11Zn > TiW11Fe >> H3PW12O40 (PW12). The selected POMs showed good stability during the reactions. Karl Fischer analysis, ICPE (Inductive Coupled Plasma Emission) and FT-IR (Fourier Transform Infrared Spectroscopy) were used to confirm the composition and structure. UV-Vis absorption spectra, kinetics investigation and cyclic voltammetric characterizations were used to explain the photocatalytic results. Finally, an analogous "Z-scheme'' mechanism was proposed for the homogeneous systems toward photocatalytic H-2 evolution under simulated solar light irradiation.The photocatalytic hydrogen (H-2) evolution with transition-metal substituted Keggin-type titanium tungstates Na-5(6)[MTiW11O39]center dot xH(2)O (abbreviated as TiW11M (M = Fe, Co, Zn)) as photocatalyst was reported. They showed good photocatalytic activities toward H-2 evolution in homogeneous systems under simulated solar light irradiation. The order of photocatalytic activity was TiW11Co approximate to TiW11Zn > TiW11Fe >> H3PW12O40 (PW12). The selected POMs showed good stability during the reactions. Karl Fischer analysis, ICPE (Inductive Coupled Plasma Emission) and FT-IR (Fourier Transform Infrared Spectroscopy) were used to confirm the composition and structure. UV-Vis absorption spectra, kinetics investigation and cyclic voltammetric characterizations were used to explain the photocatalytic results. Finally, an analogous "Z-scheme'' mechanism was proposed for the homogeneous systems toward photocatalytic H-2 evolution under simulated solar light irradiation
Estimating the value of a statistical life in China: A contingent valuation study in six representative cities
The value of a statistical life (VSL) is a crucial tool for monetizing health impacts. To explore the VSL in China, this study examines people’s willingness to pay (WTP) to reduce death risk from air pollution in six representative cities in China based on face-to-face contingent valuation interviews (n = 3 936) from March 7, 2019 to September 30, 2019. The results reveal that the WTP varied from CNY 455 to 763 in 2019 (USD 66–111), corresponding to a VSL range of CNY 3.79–6.36 million (USD 549 395–921 940). The VSL in China in 2019 is estimated to be CNY 4.76 million (USD 689 659). The statistics indicate that monthly expenditure levels, environmental concerns, risk attitudes, and assumed market acceptance, which have seldom been discussed in previous studies, significantly impact WTP and VSL. These findings will serve as a reference for analyzing mortality risk reduction benefits in future research and for policymaking
Phys. Chem. Chem. Phys.
rGO-CdS-H2W12 nanocomposite film was successfully fabricated by a layer-by-layer self-assembly method. The composite film was characterized by techniques such as UV-Vis spectra, XPS, and AFM. The composite film showed high photoelectronic response under the illumination of sunlight. Both current-voltage curves and photocurrent transient measurements demonstrated that the photocurrent response of the rGO-CdS-H2W12 composite film was enhanced five-fold compared with CdS film. This can be attributed to the photoinduced electron transfer between CdS, H2W12 and rGO, which promotes the charge separation efficiency of CdS. The introduction of GO enhanced the charge separation and transportation. More importantly, various pollutants can be treated as electron donors, and can thus be degraded and produce hydrogen at the same time, at a low bias voltage under the irradiation of solar light.rGO-CdS-H2W12 nanocomposite film was successfully fabricated by a layer-by-layer self-assembly method. The composite film was characterized by techniques such as UV-Vis spectra, XPS, and AFM. The composite film showed high photoelectronic response under the illumination of sunlight. Both current-voltage curves and photocurrent transient measurements demonstrated that the photocurrent response of the rGO-CdS-H2W12 composite film was enhanced five-fold compared with CdS film. This can be attributed to the photoinduced electron transfer between CdS, H2W12 and rGO, which promotes the charge separation efficiency of CdS. The introduction of GO enhanced the charge separation and transportation. More importantly, various pollutants can be treated as electron donors, and can thus be degraded and produce hydrogen at the same time, at a low bias voltage under the irradiation of solar light
High nuclearity Co polyoxometalate based artificial photosynthesis for solar hydrogen generation
The photocatalytic hydrogen (H-2) generation by the high nuclearity Co substituted polyoxometalates (PoMs), K10Na12[{Co-3(B-beta-SiW9O33(OH))(B-beta-SiW8O29 (OH)(2))}(2)]center dot 49H(2)O (abbreviated as CoPOM) was reported. Owing to the multielectron redox capabilities of the high nuclearity CoPOM, the POM showed excellent photocatalytic activities toward H-2 evolution in both molecule scale (homogeneous) and composite (heterogeneous) systems. The photocatalytic activities of CoPOM were much better than H3PW12O40. UV-Vis-NIR absorption spectral, Raman spectral, cyclic voltammetric behavior and intermittent photoelectrochemical current response were used to characterize the structure of the TiO2/CoPOM composite and interaction between TiO2 and CoPOM. Analogous "Z-scheme" and "dye" sensitized mechanisms were proposed for the homogeneous and heterogeneous systems toward photocatalytic H-2 evolution under solar light irradiation, respectively. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved
Transcriptome Analysis Reveals Cross-Talk between the Flagellar Transcriptional Hierarchy and Secretion System in <i>Plesiomonas shigelloides</i>
Plesiomonas shigelloides, a Gram-negative bacillus, is the only member of the Enterobacteriaceae family able to produce polar and lateral flagella and cause gastrointestinal and extraintestinal illnesses in humans. The flagellar transcriptional hierarchy of P. shigelloides is currently unknown. In this study, we identified FlaK, FlaM, FliA, and FliAL as the four regulators responsible for polar and lateral flagellar regulation in P. shigelloides. To determine the flagellar transcription hierarchy of P. shigelloides, the transcriptomes of the WT and ΔflaK, ΔflaM, ΔfliA, and ΔfliAL were carried out for comparison in this study. Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and luminescence screening assays were used to validate the RNA-seq results, and the Electrophoretic Mobility Shift Assay (EMSA) results revealed that FlaK can directly bind to the promoters of fliK, fliE, flhA, and cheY, while the FlaM protein can bind directly to the promoters of flgO, flgT, and flgA. Meanwhile, we also observed type VI secretion system (T6SS) and type II secretion system 2 (T2SS-2) genes downregulated in the transcriptome profiles, and the killing assay revealed lower killing abilities for ΔflaK, ΔflaM, ΔfliA, and ΔfliAL compared to the WT, indicating that there was a cross-talk between the flagellar hierarchy system and bacterial secretion system. Invasion assays also showed that ΔflaK, ΔflaM, ΔfliA, and ΔfliAL were less effective in infecting Caco-2 cells than the WT. Additionally, we also found that the loss of flagellar regulators causes the differential expression of some of the physiological metabolic genes of P. shigelloides. Overall, this study aims to reveal the transcriptional hierarchy that controls flagellar gene expression in P. shigelloides, as well as the cross-talk between motility, virulence, and physiological and metabolic activity, laying the groundwork for future research into P. shigelloides’ coordinated survival in the natural environment and the mechanisms that infect the host
Nanoscale
Fuel cells and metal-air batteries will only become widely available in everyday life when the expensive platinum-based electrocatalysts used for the oxygen reduction reactions are replaced by other efficient, low-cost and stable catalysts. We report here the use of nitrogen-doped graphdiyne as a metal-free electrode with a comparable electrocatalytic activity to commercial Pt/C catalysts for the oxygen reduction reaction in alkaline fuel cells. Nitrogen-doped graphdiyne has a better stability and increased tolerance to the cross-over effect than conventional Pt/C catalysts.Fuel cells and metal-air batteries will only become widely available in everyday life when the expensive platinum-based electrocatalysts used for the oxygen reduction reactions are replaced by other efficient, low-cost and stable catalysts. We report here the use of nitrogen-doped graphdiyne as a metal-free electrode with a comparable electrocatalytic activity to commercial Pt/C catalysts for the oxygen reduction reaction in alkaline fuel cells. Nitrogen-doped graphdiyne has a better stability and increased tolerance to the cross-over effect than conventional Pt/C catalysts