A model for the prediction of laminar-turbulent transition processes was formulated. It is based on the LCTM ('Local Correlation-based Transition Modelling') concept, where experimental correlations are being integrated into standard convection-diffusion transport equations using local variables. The starting point for the model was the γ -Re θ model already widely used in aerodynamics and turbomachinery CFD applications. Some of the deficiencies of the γ -Re θ model, like the lack of Galilean invariance were removed. Furthermore, the Re θ equation was avoided and the correlations for transition onset prediction have been significantly simplified. The model has been calibrated against a wide range of Falkner-Skan flows and has been applied to a variety of test cases.

Bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are very crucial for converting water into clean fuel through overall water splitting. Here, we report on a bifunctional catalyst based on Ir-doped NiV layered double hydroxide with Ir−O−V catalytic groups on which water dissociation, HER, and OER occur on Ir, bridge O, and V atoms, respectively. Interestingly, the dopant Ir ions were found to play a triple role: (i) serve as catalytic sites for water dissociation, (ii) reduce charge density on adjacent bridge oxygen, thus facilitating HER there, and (iii) increase charge density on V ions, which in turn boosts OER. As a result, the catalyst achieves an ultralow applied voltage for overall water splitting (1.49 V @ 10 mA cm −2 ) and beats the noble metallic couple Pt/C and Ir/C with its value of 1.60 V @ 10 mA cm −2 .

RNA N6-methyladenosine (m6A) modification occurs in approximately 25% of mRNAs at the transcriptome-wide level. RNA m6A is regulated by the RNA m6A methyltransferases methyltransferase-like 3 (METTL3), METTL14, and METTL16 (writers), demethylases FTO and ALKBH5 (erasers), and binding proteins YTHDC1–2, YTHDF1–3, IGF2BP1–3, and SND1 (readers). These RNA m6A modification proteins are frequently upregulated or downregulated in human cancer tissues and are often associated with poor patient prognosis. By modulating pre-mRNA splicing, mRNA nuclear export, decay, stability, and translation of oncogenic and tumor suppressive transcripts, RNA m6A modification proteins regulate cancer cell proliferation, survival, migration, invasion, tumor initiation, progression, metastasis, and sensitivity to anticancer therapies. Importantly, small-molecule activators of METTL3, as well as inhibitors of METTL3, FTO, ALKBH5, and IGF2BP1 have recently been identified and have shown considerable anticancer effects when administered alone or in combination with other anticancer agents, both in vitro and in mouse models of human cancers. Future compound screening and design of more potent and selective RNA m6A modification protein inhibitors and activators are expected to provide novel anticancer agents, appropriate for clinical trials in patients with cancer tissues harboring aberrant RNA m6A modification protein expression or RNA m6A modification protein–induced resistance to cancer therapy.

Restenosis and thrombosis formation after cardiovascular devices implantation continue to be problematic. Although various platforms and parameters of cardiovascular devices have been designed and optimized over the years, postoperative complications are hard to avoid. The native vascular endothelium always provide a nonthrombogenic surface as well as prevent intimal overproliferation, thereby, the presence of a confluent endothelial cell layer on material surfaces have been widely accepted as an ideal approach to improve the biocompatibility of implanted cardiovascular materials. Endothelialization on biomaterial surfaces is initially developed by in vitro cell seeding. However, numerous no-perfect parts of this method are existed for clinical use. The emergency of endothelial progenitor cells may provide a promising way for setting these limitations. Over the last decades, countless researches about EPCs-based in vivo induced self-endothelialization have been reported and mainly focused on cellular therapy, pharmacological therapy, materials designing, or surface biofunctional modification. This review details the development of endothelialization on cardiovascular material surfaces from in vitro to in vivo. Endothelialization progress on the basis of molecular biological level and bioinformatics theory is expected to be the key point in the coming decades.

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Microcellular polyetherimide (PEI) foams were prepared by microcellular injection molding using supercritical nitrogen (SC-N 2 ) as foaming agent. The effects of four different processing parameters including shot size, injection speed, SC-N 2 content, and mold temperature on cell morphology and material properties were studied. Meanwhile, multiwalled carbon nanotube (MWCNT), nano-montmorillonoid (NMMT), and talcum powder (Talc) were introduced into PEI matrix as heterogeneous nucleation agents in order to further improve the cell morphology and mechanical properties of microcellular PEI foams. The results showed that the processing parameters had great influence on cell morphology. The lowest cell size can reach to 18.2 lm by optimizing the parameters of microcellular injection molding. Moreover, MWCNT can remarkably improve the cell morphology of microcellular PEI foams. It was worth mentioning that when the MWCNT content was 1 wt %, the microcellular PEI/MWCNT foams displayed optimum mechanical properties and the cell size decreased by 28.3% compared with microcellular PEI foams prepared by the same processing parameters.

SUMMARYAn extensive programme of full-scale ambient vibration tests has been conducted to measure the dynamic response of a 542 m (centre span of 274 m) cable-stayed bridge-the Quincy Bayview Bridge in Illinois. A microcomputer-based system was used to collect and analyse the ambient vibration data. A total of 25 modal frequencies and associated mode shapes were identified for the deck structure within the frequency range of 0-2 Hz. Also, estimations were made for damping ratios. The experimental data clearly indicated the occurrence of many closely spaced modal frequencies and spatially complicated mode shapes. Most tower modes were found to be associated with the deck modes, implying a considerable interaction between the deck and tower structure. No detectable levels of motion were evident at the foundation support of the pier. The results of the ambient vibration survey were compared to modal frequencies and mode shapes computed using a three-dimensional finite element model of the bridge. For most modes, the analytic and experimental modal frequencies and mode shapes compare quite well, especially for the vertical modes. Based on the findings of this study, a linear elastic finite element model appears to be capable of capturing much of the complex dynamic behaviour of the bridge with very good accuracy, when compared to the low-level dynamic responses induced by ambient wind and traffic excitations.

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