A theoretical investigation of differential, integrated elastic, inelastic, transport (momentum transfer & viscosity), grand total (elastic+inelastic) and total ionisation cross-sections along with ...the Sherman functions for the scattering of electron and positron by hydrogen cyanide (HCN) in the energy range
$ 1\,{\rm eV}-1 $
1
e
V
−
1
MeV are presented in this report. We perform calculations using the single scattering independent atom model (IAM) and IAM with screening correction (IAMS). The scattering observables are calculated using a complex optical model potential in the framework of the Dirac partial wave analysis (DPWA). The inclusion of screening correction to the IAM appreciably improves the cross-sections, especially at low-impact energies. Our calculated results are compared with the available experimental and theoretical works found in the literature. Our present computational data agree well with prior results.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Nanostructured WC–Co and WC–Co–Al coatings, with about 300-μm as-deposited coating thickness, were deposited by high velocity oxy-fuel (HVOF) spraying. Agglomerated nanostructured cermet powders ...produced by the Mechanomade® process was used for HVOF spraying. Dense and well-adherent coatings with crystal sizes below 30nm were deposited on stainless steel 304 substrate. Porosity was less than 5% and the bond strength with the substrate was around 60MPa. Experimental data on friction, wear, and abrasion resistance revealed that nanostructured WC–Co based coatings containing some Al as alloying element, exhibit improved tribological characteristics in comparison to nanostructured and micron-sized WC–Co coatings. This was attributed to a carbide particle distribution within the coating revealed by SEM, the absence of brittle W2C-like phases revealed by XRD, and the presence of Al at particle/matrix boundaries revealed by TEM.
► Nanostructured WC–Co coatings were deposited through HVOF process. ► Presently investigated nanostructured WC–Co coatings are free from brittle W2C like phases. ► Wear resistance of nanostructured coatings is better than micron sized coatings. ► Small amount Al addition in the coatings exhibit better wear resistance. ► Al helps to prevent decarburization as well as increase cohesion in the coatings.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
RATIONALE:Activated nuclear factor (NF)-κB signaling in the vascular endothelium promotes the initiation and progression of atherosclerosis. Targeting endothelial NF-κB may provide a novel strategy ...to limit chronic inflammation.
OBJECTIVE:To examine the role of microRNA-181b (miR-181b) in endothelial NF-κB signaling and effects on atherosclerosis.
METHODS AND RESULTS:MiR-181b expression was reduced in the aortic intima and plasma in apolipoprotein E–deficient mice fed a high-fat diet. Correspondingly, circulating miR-181b in the plasma was markedly reduced in human subjects with coronary artery disease. Systemic delivery of miR-181b resulted in a 2.3-fold overexpression of miR-181b in the aortic intima of apolipoprotein E–deficient mice and suppressed NF-κB signaling revealed by bioluminescence imaging and reduced target gene expression in the aortic arch in apolipoprotein E–deficient/NF-κB-luciferase transgenic mice. MiR-181b significantly inhibited atherosclerotic lesion formation, proinflammatory gene expression and the influx of lesional macrophages and CD4+ T cells in the vessel wall. Mechanistically, miR-181b inhibited the expression of the target gene importin-α3, an effect that reduced NF-κB nuclear translocation specifically in the vascular endothelium of lesions, whereas surprisingly leukocyte NF-κB signaling was unaffected despite a 7-fold overexpression of miR-181b. Our findings uncover that NF-κB nuclear translocation in leukocytes does not involve importin-α3, but rather importin-α5, which miR-181b does not target, highlighting that inhibition of NF-κB signaling in the endothelium is sufficient to mediate miR-181b’s protective effects.
CONCLUSIONS:Systemic delivery of miR-181b inhibits the activation of NF-κB and atherosclerosis through cell-specific mechanisms in the vascular endothelium. These findings support the rationale that delivery of miR-181b may provide a novel therapeutic approach to treat chronic inflammatory diseases such as atherosclerosis.
Abstract Wound healing is a physiological reparative response to injury and a well-orchestrated process that involves hemostasis, cellular migration, proliferation, angiogenesis, extracellular matrix ...deposition, and wound contraction and re-epithelialization. However, patients with type 2 diabetes mellitus (T2D) are frequently afflicted with impaired wound healing that progresses into chronic wounds or diabetic ulcers, and may lead to complications including limb amputation. Herein, we investigate the potential role of microRNA-26a (miR-26a) in a diabetic model of wound healing. Expression of miR-26a is rapidly induced in response to high glucose in endothelial cells (ECs). Punch skin biopsy wounding of db/db mice revealed increased expression of miR-26a (~ 3.5-fold) four days post-wounding compared to that of WT mice. Local administration of a miR-26a inhibitor, LNA-anti-miR-26a, induced angiogenesis (up to ~ 80%), increased granulation tissue thickness (by 2.5-fold) and accelerated wound closure (53% after nine days) compared to scrambled anti-miR controls in db/db mice. These effects were independent of altered M1/M2 macrophage ratios. Mechanistically, inhibition of miR-26a increased its target gene SMAD1 in ECs nine days post-wounding of diabetic mice. In addition, high glucose reduced activity of the SMAD1-3′-UTR. Diabetic dermal wounds treated with LNA-anti-miR-26a had increased expression of ID1, a downstream modulator or SMAD1, and decreased expression of the cell cycle inhibitor p27. These findings establish miR-26a as an important regulator on the progression of skin wounds of diabetic mice by specifically regulating the angiogenic response after injury, and demonstrate that neutralization of miR-26a may serve as a novel approach for therapy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Mechanical alloying (MA) of Ni and P powders containing 20 and 12 wt% P was investigated. The structural changes of alloys during mechanical alloying were studied by X-ray diffractometry and ...transmission electron microscopy. The results showed that the interdiffusion of Ni and P elements during MA of Ni
80
P
20
alloy leads to the development of Ni
12
P
5
and Ni
2
P intermetallic compounds. However MA of the Ni
88
P
12
alloy leads to the formation of an intermetallic compound (Ni
3
P) and a solid solution (α-Ni) as well as partially amorphous structure. Intermediate annealing of MAed Ni
88
P
12
alloy does not promote the formation of fully amorphous structure. Furthermore, thermodynamic analysis using the Miedema’s semi-empirical model showed that the intermetallic phases are the most stable phases in Ni
88
P
12
and Ni
80
P
20
alloys during MA.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•The presence and size of particles affected the fatigue life significantly.•Balance of strain hardening and heat generation reduce feed and speed effects.•The interactions of different parameters ...significantly affect fatigue life.•Smaller or no particles induces a complete separation of failed samples.•Cracks are arrested or deflected by the bigger reinforced particles.
The high cycle constant stress amplitude fatigue performance of metal matrix composite (MMC) components machined by a milling process was investigated in this study as a function of machining speed, feed rate and reinforcement particle size. The presence of reinforcement and particle size were found to be the most influential factors that affected the fatigue life. In contrast to this, the effect of feed and speed on tool-particle interaction, strain hardening and heat generation during milling of MMCs were balanced in such a way that the contributions of feed and speed on fatigue life were negligible. The interactions of different parameters contributed significantly to the fatigue life which indicated that the modelling of fatigue life based on these three parameters was relatively complex. The fatigue life of the machined MMC samples increased with decreasing particle size and increasing feed. However, the fatigue life was not influenced by speed variation. The presence of smaller or no particles induced a complete separation of failed samples, in contrast to that of specimens containing larger reinforcing particles where crack growth was arrested or deflected by the reinforcing particles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Inconel 718, a Ni-based superalloy, was prepared by powder laser bed fusion (P-LBF) additive manufacturing (AM) method. AM of the Inconel 718 is challenging, as this particular alloy possesses a ...higher melting point, as well as resistance to temperature, which induces ‘hot-cracking’. Thus, the selection of proper input parameters are essential, which was successfully achieved in this present study. The microstructure exhibits a hierarchical structure, that starts with equiaxed and sub-cellular (∼100–600 nm) grains, and ends up on the formation of melt-pool and grain boundaries. This structure is exceptional and completely dissimilar to that of wrought alloy, which is infested with twins and precipitates of different secondary phases. However, the effectiveness of such microstructure of L-PBF alloy towards material's strength was undermined, as it lacks the presence of abundant precipitates, which is the major contributor to the strength of such alloys. The strength of the L-PBF processed alloy was in the range of 413–491 MPa and 562–665 MPa respectively, for yield and ultimate compressive strength. This was marginally higher than that of wrought alloy (408 MPa of Yield and 656 MPa of compressive strength). This was attributed to the absence of abundant gamma/gamma double prime (γ'/γ'') phases, and the presence of laves and delta (δ) phases, that are inferior towards the overall strengthen of the Inconel 718. Cross-sectional SEM and TEM investigation of the deformed micro-pillars confirmed the prevailing deformation mechanism that can be attributed to the slip/share plane formation in the presence of dislocation loops.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Nanostructured WC–12Co coating with crystal sizes below 30nm were deposited on low carbon steel substrate by high velocity oxy-fuel spraying. In this study, corrosion behavior of such coatings was ...investigated in artificial sea water electrolyte and compared with micron-sized (internal structure) coating of similar composition. Besides that, role of small amount Al alloying on corrosion behavior of such nanostructured coating was also investigated. Nanostructured WC–12Co coatings with or without Al exhibit lower corrosion potential and lower polarization resistance compared to micron-sized (internal structure) coating as well as higher Co dissolution as revealed by electrochemical impedance spectroscopy (EIS) together with other complementary electrochemical techniques.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Thermodynamic expression of the Gibbs free energy indicates existence of a miscibility gap in the α-solid solution of Ti-Zr system; with the apex of the miscibility gap at 308 K, XZr = 0.5. Thermal ...aging and experimental observation of the phase separation is not possible due to the unfavorable kinetics. Ab-initio calculations confirm positive energy of formation as well as favors large Zr-Zr distance in the solution phase. Extended X-ray Absorption Fine Structure results suggest non-random solution structure in the HCP α-phase much above the critical temperature. Therefore, existence of a miscibility gap could be predicted from the non-random solid solution structure of the parent α-phase.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper reports on the differential, integral, momentum transfer and viscosity cross sections along with spin polarisation for elastically scattered electrons and positrons from iron atoms in the ...incident energy (
) range
eV. In addition, we report here systematically the details of the critical minima in the elastic differential cross sections, and the absorption and total cross sections. An optical model using a complex optical potential, composed of static, exchange, polarisation and imaginary terms, is used to solve the Dirac relativistic equation in partial-wave analysis. A comparison of our evaluated cross sections with the available experimental data and other theoretical findings shows a reasonable agreement over the studied energy range.
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