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In this work, a tube extrusion-shear-expanding (TESE) process was proposed to develop a high-performance magnesium alloy thin-walled tube, and then a comparison was made with the direct extrusion (DE) process. The microstructure and mechanical properties of magnesium alloy tubes under different processes were tested and analyzed. Numerical simulations were conducted by using DEFORMTM-3D software to predict the effective stresses, forming loads, and effective strains during the forming of magnesium alloy tubes. Compared with DE process, the TESE process with high effective stresses, effective strains, and forming loads generates a severe plastic deformation of the tube, leading to a more obvious grain refinement effect on the fabricated tube with a tensile strength of around 293 MPa and an elongation of around 15%. The results show that the TESE process has obvious advantages. The critical shear force and dynamic recrystallization further refine the grains and weaken the basal texture strength. The comprehensive performance of magnesium alloy tube is improved. [ABSTRACT FROM AUTHOR]

The efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) in patients with non-small cell lung cancer (NSCLC) is related to EGFR mutations. Although the p.L858R point mutation in exon 21 and the in-frame deletion mutation in exon 19 are well known, efficacy of EGFR-TKI in patients with more than one EGFR mutation is not well understood. 799 NSCLC patients were screened for EGFR mutations. Of the 799 patients, 443 (55.4%) had mutations, out of which 22 (2.75%) had multiple complex mutations. Most multiple mutations (20/22) harbored common mutations such as the p.L858R point mutation in exon 21 and the in-frame deletion mutation in exon 19. 11 out of 22 patients who had multiple EGFR mutations underwent TKI therapy and primary end-points of progression free and overall survival were determined. Our analysis revealed that cases with multiple mutations had similar end-point outcomes as single mutation to TKI therapy. Report of these cases will be helpful in decision making for treatment of NSCLC patients harboring multiple EGFR mutations. [ABSTRACT FROM AUTHOR]

In this paper, we propose the analytical solution of nano-rod antennas utilizing a cylindrical harmonics expansion. By treating the metallic nano-rods as plasmonic cavities, we derive closed-form expressions for both the internal and the radiated fields, as well as the resonant condition and the radiation efficiency. With our theoretical model, we show that besides the plasmonic resonances, efficient radiation takes advantage of (a) rendering a large value of the rods' radius and (b) a central-fed profile, through which the radiation efficiency can reach up to 70% and even higher in a wide frequency band. Our theoretical expressions and conclusions are general and pave the way for engineering and further optimization of optical antenna systems and their radiation patterns. [ABSTRACT FROM AUTHOR]

DNA replication is essential for accurate transmission of genomic information from parental to daughter cells. DNA replication is licensed once per cell division cycle. This process is highly regulated by both positive and negative regulators. Over-replication, under-replication, as well as DNA damage in a cell all induce the activation of checkpoint control pathways such as ATM/ATR, CHK kinases, and the tumor suppressor protein p53, which provide 'damage controls' via either DNA repairs or apoptosis. This review focuses on accumulating evidence, with the emphasis on recently discovered Killin, that S-phase checkpoint control is crucial for a mammalian cell to make a life and death decision in order to safeguard genome integrity. [ABSTRACT FROM AUTHOR]

Context: The reaction between Na and HF is a typical harpooning reaction which is of great interest due to its significance in understanding the elementary chemical reaction kinetics. This work aims to investigate the detailed reaction mechanisms of sodium with hydrogen fluoride and the adsorption of HF on the resultant NaF as well as the (NaF)4 tetramer. The results suggest that the reaction between Na and HF leads to the formation of sodium fluoride salt NaF and hydrogen gas. Na interacts with HF to form a complex HF···Na, and then the approaching of F atom of HF to Na results in a transition state H···F···Na. Accompanied by the broken of H-F bond, the bond forms between F and Na atoms as NaF, then the product NaF is yielded due to the removal of H atom. The resultant NaF can further form (NaF)4 tetramer. The interaction of NaF with HF leads to the complex NaF···HF; the form I as well as II of (NaF)4 can interact with HF to produce two complexes (i.e., (NaF)4(I-1)···HF, (NaF)4(I-2)···HF, (NaF)4(II-1)···HF and (NaF)4(II-2)···HF), but the form III of (NaF)4 can interact with HF to produce only one complex (NaF)4(III)···HF. These complexes were explored in terms of noncovalent interaction (NCI) and quantum theory of atoms in molecules (QTAIM) analyses. NCI analyses confirm the existences of attractive interactions in the complexes HF···Na, NaF···HF, (NaF)4(I-1)···HF, (NaF)4(I-2)···HF, (NaF)4(II-1)···HF and (NaF)4(II-2)···HF, and (NaF)4(III)···HF. QTAIM analyses suggest that the F···Na interaction forms in the HF···Na complex while the F···H hydrogen bonds form in NaF···HF, (NaF)4(I-1)···HF, (NaF)4(I-2)···HF, (NaF)4(II-1)···HF and (NaF)4(II-2)···HF, and (NaF)4(III)···HF complexes. Natural bond orbital (NBO) analyses were also applied to analyze the intermolecular donor-acceptor orbital interactions in these complexes. These results would provide valuable insight into the chemical reaction of Na and HF and the adsorption interaction between sodium fluoride salt and HF. Methods: The calculations were carried out at the M06-L/6-311++G(2d,2p) level of theory which were performed using the Gaussian16 program. Intrinsic reaction coordinate (IRC) calculations were carried out at the same level of theory to confirm that the obtained transition state was true. The molecular surface electrostatic potential (MSEP) was employed to understand how the complex forms. Quantum theory of atoms in molecules (QTAIM) and noncovalent interaction (NCI) analysis was used to know the topology parameters at bond critical points (BCPs) and intermolecular interactions in the complex and intermediate. The topology parameters and the BCP plots were obtained by the Multiwfn software. [ABSTRACT FROM AUTHOR]

Acoustic emission signals are relevant to the process of rock failure. In this paper, acoustic emission waveform signals during rock loading are acquired through uniaxial compression test of granite in laboratory. Short-time Fourier transform is used to analyze the acoustic emission signals during rock fracture to obtain the peak frequency. Based on the peak frequency of acoustic emission, four types of acoustic emission signals are classified by using fuzzy C-means method. The parameters of different types of acoustic emission signals are analyzed, which include ring count, duration, amplitude and energy. Meanwhile, the progressive propagation of surface cracks in rock specimens is quantitatively analyzed by digital image correlation (DIC) technology. The result shows that different types of acoustic emission signals correspond to different strength of rock fracture. Before rock fracture, high-count, long-duration and high-energy precursory characteristic signals appear intensively. The event density Den t = 1 is taken as the early warning threshold of rock fracture through the quantitative analysis of acoustic emission signal. The present results of the research show the usefulness of the DIC and acoustic emission techniques in experiment of that type. [ABSTRACT FROM AUTHOR]

In pondering of new promising transparent conductors to replace the cost rising tin-doped indium oxide (ITO), metal nanowires have been widely concerned. Herein, we demonstrate an approach for successful synthesis of long and fine Cu nanowires (NWs) through a novel catalytic scheme involving nickel ions. Such Cu NWs in high aspect ratio (diameter of 16.2 ± 2 nm and length up to 40 mm) provide long distance for electron transport and, meanwhile, large space for light transmission. Transparent electrodes fabricated using the Cu NW ink achieve a low sheet resistance of 1.4 Ohm/sq at 14% transmittance and a high transparency of 93.1% at 51.5 Ohm/sq. The flexibility and stability were tested with 100-timebending by 180° and no resistance change occurred. Ohmic contact was achieved to the p- and n-GaN on blue light emitting diode chip and bright electroluminescence from the front face confirmed the excellent transparency. [ABSTRACT FROM AUTHOR]

The MGSA/GRO protein is endogenously expressed in almost 70% of the melanoma cell lines and tumors, but not in normal melanocytes. We have previously demonstrated that over-expression of human MGSA/GROα, β or γ in immortalized murine melanocytes (melan-a cells) enables these cells to form tumors in SCID and nude mice. To examine the possibility that the MGSA/GRO effect on melanocyte transformation requires expression of other genes, differential display was performed. One of the mRNA's identified in the screen as overexpressed in MGSA/GRO transformed melan-a clones was the newly described M-Ras or R-Ras3 gene, a member of the Ras gene superfamily. Over-expression of MGSA/GRO upregulates M-Ras expression at both the mRNA and protein levels, and this induction requires an intact glutamine-leucine-arginine (ELR)-motif in the MGSA/GRO protein. Western blot examination of Ras expression revealed that K- and N-Ras proteins are also elevated in MGSA/GRO-expressing melan-a clones, leading to an overall increase in the amount of activated Ras. MGSA/GRO-expressing melan-a clones exhibited enhanced AP-1 activity. The effects of MGSA/GRO on AP-1 activation could be mimicked by over-expression of wild-type M-Ras or a constitutively activated M-Ras mutant in control melan-a cells as monitored by an AP-1-luciferase reporter, while expression of a dominant negative M-Ras blocked AP-1-luciferase activity in MGSA/GRO-transformed melan-a clones. In the in vitro transformation assay, over-expression of M-Ras mimicked the effects of MGSA/GRO by inducing cellular transformation in control melan-a cells, while over-expression of dominant negative M-Ras in MGSA/GROα-expressing melan-a-6 cells blocked transformation. These data suggest that MGSA/GRO-mediated transformation requires Ras activation in melanocytes. Oncogene (2000) 19, 4647–4659 [ABSTRACT FROM AUTHOR]

Oncogenic mutations in ras lead to constitutive activation of downstream signaling pathways that modulate the activities of transcription factors. In turn, these factors control the expression of a subset of genes responsible for neoplastic cell transformation. Recent studies suggest that transcription factor NF-κB contributes to cell transformation by inhibiting the cell death signal activated by oncogenic Ras. In this study, inhibition of NF-κB activity by forced expression of a super-repressor form of IκBα, the major inhibitor of NF-κB, markedly decreased the growth rate, saturation density and tumorigenicity of oncogenic H-Ras transformed rat embryo fibroblasts. Such clonally isolated cells overexpressing IκBα super-repressor not only were viable but also exhibited no sign of spontaneous apoptosis. Inhibition of NF-κB in these cells was functionally demonstrated by both the loss of cytokine induced DNA binding activity and a profoundly increased sensitivity to cell death in response to TNF-α treatment. In contrast, inhibition of NF-κB activity in non-transformed fibroblasts had minimal effect on growth, but rendered the cells resistant to a subsequent transformation by H-ras oncogene. Similar results were also obtained with rat intestinal epithelial cells harboring an inducible ras oncogene. Taken together, these findings suggest that NF-κB activity is essential for abnormal cell proliferation and tumorigenicity activated by the ras oncogene and highlight an alternative functional role for NF-κB in oncogenic Ras-mediated cell transformation that is distinct from its anti-apoptotic activity. Oncogene (2000) 19, 841–849. [ABSTRACT FROM AUTHOR]

Mutations in the ras oncogenes have been linked to many different cancers. In contrast to the extensive body of knowledge related to the genetics of ras activation, relatively little is known of the transcriptional events triggered by ras. In previous work we have used differential display to identify Mob-1, a member of α-chemokine family, as one of the immediate transcriptional targets following Ras activation. Here, we provide additional experimental evidence to support this finding by the use of an inducible H-ras expression system, the treatment of Ras farnesyl transferase inhibitor and activation of endogenous Ras by serum growth factors. We further demonstrate that IP-10, the human homolog of Mob-1, is overexpressed in the majority of colorectal cancers. [ABSTRACT FROM AUTHOR]

Multi-structured Ag/MnO2-cordierite molded catalysts were prepared by hydrothermal method and applied to the catalytic oxidation of VOCs. Catalytic activities of Ag/MnO2-cordierite were evaluated by 1000 ppm of toluene, ethyl acetate and chlorobenzene degradation respectively at the air atmosphere, and their physicochemical properties were characterized through multiple techniques containing XRD, SEM, TEM, H2-TPR and XPS. It is found that nanorod Ag/MnO2-cordierite molded catalyst showed prominent catalytic activity for VOCs decomposition and the T90 for toluene, ethyl acetate and chlorobenzene are 275 °C, 217 °C and 385 °C respectively under the space velocity of 10,000 h−1. High valence manganese oxide, more active lattice oxygen proportion and superior low-temperature reducibility were the great contributors to the high activity of the catalyst with nanorod morphology. Studies of space velocity and catalytic stability over nanorod Ag/MnO2-cordierite molded catalyst have confirmed the good catalytic performance, excellent mechanical strength and satisfied anti-toxicity to Cl at higher space velocity, which indicates that this molded catalyst have promise for industrial application. [ABSTRACT FROM AUTHOR]

Conventional wastewater purification technologies consume large amounts of energy, while the abundant chemical energy and nutrient resources contained in sewage are wasted in such treatment processes. A microbial nutrient recovery cell (MNRC) has been developed to take advantage of the energy contained in wastewater, in order to simultaneously purify wastewater and recover nutrient ions. When wastewater was circulated between the anode and cathode chambers of the MNRC, the organics (COD) were removed by bacteria while ammonium and phosphate (NH4+-N and PO43−-P) were recovered by the electrical field that was produced using in situ energy in the wastewater without additional energy input. The removal efficiencies from wastewater were >82% for COD, >96% for NH4+-N, and >64% for PO43−-P in all the operational cycles. Simultaneously, the concentrations of NH4+ and PO43− in the recovery chamber increased to more than 1.5 and 2.2 times, respectively, compared with the initial concentrations in wastewater. The MNRC provides proof-of-concept as a sustainable, self-driven approach to efficient wastewater purification and nutrient recovery in a comprehensive bioelectrochemical system. [ABSTRACT FROM AUTHOR]