An overall historical survey on the bending and shearing deformation concepts in first-order shear deformation theories is carried out in relation to the corrected classical models from the viewpoint ...of distinguishability of both the deflections in beams and plates, including the alternative deformation concept for the Timoshenko beam and Mindlin plate models proposed by the author and his co-worker. The survey shows that in the corrected classical models, the bending and shearing deflections are recognized as distinguishable physical entities, and which has gained widespread acceptance in the various fields of continuum and structure mechanics, though both deflections cannot be obtained concurrently using a deductive approach. With regard to the conventional first-order shear deformation theory, both deflections are not to be recognized as distinguishable physical entities, and it is shown that these two deflections cannot be uniquely determined for a beam and cannot be specifically defined for a plate. In contrast to this, the alternative deformation concept is shown to be effective in resolving all the above inconsistencies. To demonstrate its effectiveness and practical advantages, both static and dynamic analyses are carried out. The static analysis involves a simply supported beam subjected to a uniform or concentrated static load, for which both the bending and shearing deflections are obtained concurrently and uniquely in addition to the total deflection using a deductive approach, and a thought experiment that distinguishes both deflections as physical entities is also presented. The dynamic analysis involves the application of an extension of the Southwell–Dunkerley methods for synthesizing frequencies. Based on a series-type synthetic-frequency method established by the author and his co-worker, a frequency analysis with two deflections coupled in series is carried out for isotropic plates and carbon fiber reinforced plastic laminated composite beams. It is also shown that the alternative deformation concept is a model that can contribute to the development of a practical finite element formulation that is free from shear locking.
Amphotericin B (AmB) is a prototypical small molecule natural product that can form ion channels in living eukaryotic cells and has remained refractory to microbial resistance despite extensive ...clinical utilization in the treatment of life-threatening fungal infections for more than half a century. It is now widely accepted that AmB kills yeast primarily via channel-mediated membrane permeabilization. Enabled by the iterative cross-coupling-based synthesis of a functional group deficient derivative of this natural product, we have discovered that channel formation is not required for potent fungicidal activity. Alternatively, AmB primarily kills yeast by simply binding ergosterol, a lipid that is vital for many aspects of yeast cell physiology. Membrane permeabilization via channel formation represents a second complementary mechanism that further increases drug potency and the rate of yeast killing. Collectively, these findings (i) reveal that the binding of a physiologically important microbial lipid is a powerful and clinically validated antimicrobial strategy that may be inherently refractory to resistance, (ii) illuminate a more straightforward path to an improved therapeutic index for this clinically vital but also highly toxic antifungal agent, and (iii) suggest that the capacity for AmB to form proteinlike ion channels might be separable from its cytocidal effects.
•Torsional fatigue tests were carried out near the fatigue limit for annealed carbon steels with ferrite-pearlite microstructures.•Shear-mode fatigue cracks tended to propagate in the soft ferrite ...phase, avoiding the hard pearlite phase.•The interior geometry of fatigue cracks were observed by precise polishing of the specimens.•The torsional fatigue limit is determined by the threshold condition for continuous propagation of a macroscopic Mode I branched crack.
Torsional fatigue tests at an R of −1 were carried out near the fatigue limit, using smooth, round-bar specimens of annealed carbon steels with banded ferrite/pearlite and isotropic ferrite/pearlite structures. Precise polishing of the specimens made it possible to observe the interior geometry of fatigue cracks. While the crack-plane was macroscopically of shear-mode, it was irregular microscopically, bearing many kinked and branched cracks. Based on calculation of the stress intensity factor for propagating and non-propagating cracks, it was concluded that the torsional fatigue limit was determined by the threshold condition for continuous Mode I propagation into the ferrite/pearlite structure.
Magnetic tunnel junctions (MTJs) with ferromagnetic electrodes possessing a perpendicular magnetic easy axis are of great interest as they have a potential for realizing next-generation high-density ...non-volatile memory and logic chips with high thermal stability and low critical current for current-induced magnetization switching. To attain perpendicular anisotropy, a number of material systems have been explored as electrodes, which include rare-earth/transition-metal alloys, L10-ordered (Co, Fe)–Pt alloys and Co/(Pd, Pt) multilayers. However, none of them so far satisfy high thermal stability at reduced dimension, low-current current-induced magnetization switching and high tunnel magnetoresistance ratio all at the same time. Here, we use interfacial perpendicular anisotropy between the ferromagnetic electrodes and the tunnel barrier of the MTJ by employing the material combination of CoFeB–MgO, a system widely adopted to produce a giant tunnel magnetoresistance ratio in MTJs with in-plane anisotropy. This approach requires no material other than those used in conventional in-plane-anisotropy MTJs. The perpendicular MTJs consisting of Ta/CoFeB/MgO/CoFeB/Ta show a high tunnel magnetoresistance ratio, over 120%, high thermal stability at dimension as low as 40 nm diameter and a low switching current of 49 μA.
•Rosemary (Rosmarinus officinalis) extract has anthelmintic activity against monogenean (Dactylogyrus minutus) in vitro.•1,8-Cineole exhibited high anthelmintic efficacy in vitro.•We evaluated the ...efficacy of rosemary extract by bath treatment and oral administration to prevent and control monogenean infection.•Rosemary extract would be useable for control monogenean infection in aquaculture.
Monogenean parasites are important ectoparasites of fish, and are responsible for severe economic impacts in the aquaculture industry. They are usually treated with chemicals, but the chemicals can have harmful side effects in the fish and may pose threats to human health. Rosemary (Rosmarinus officinalis) is a common medicinal herb, with antimicrobial and antitumor properties. Here, we examined the anthelmintic activity of rosemary extract against the monogenean (Dactylogyrus minutus) in vitro and in vivo using bath treatment and oral administration. The in vitro experiments showed that parasite survival was affected by both rosemary extract concentration and the solvent (water and ethanol). Parasites were dead at 61.8±5.6 and 7.8±1.4min when exposed to 100 and 200g aqueous rosemary extract solution/L of water respectively. It took 166.7±48.2 and 5.4±1.01min to kill the parasites when exposed to 1 and 32g ethanol rosemary extract solution/L of water respectively. Moreover, pure component of rosemary extract obtained commercially used in in vitro experiments showed that 1,8-Cineole was the most toxic component of the main components tested. Parasite intensity and prevalence in fish exposed to 50 and 100g aqueous rosemary solution/L water for 30min were significantly lower than they were in controls (p<0.05). In oral treatment experiments, diets of Cyprinus carpio were supplemented with eight different concentrations of aqueous rosemary extract. The intensity of parasites was significantly less in fish fed for 30days with feed containing 60, 80 and 100ml aqueous extract/100g feed than in control (p<0.05). Together these results indicate that rosemary is a promising candidate for prevention and control of monogenean infection.
The use of lactic acid bacteria from human origins as a potential probiotic supplementation in aquaculture feed is now widely accepted. Here, we examined some of the properties and mechanisms of the ...action of
Lactobacillus rhamnosus GG, originating from humans, on growth performance, gut mucosal immunity and humoral and cellular immune response in tilapia (
Oreochromis niloticus). The results suggested that supplementation of
L. rhamnosus gave an advantage in promoting the intestinal structure and the mucosal immunity of tilapia. Probiotic fish had a greater villous height in all parts of the intestines and, significantly, in the proximal and middle part. The population of intraepithelial lymphocytes was significantly higher in the probiotic group than in the control group in all parts of the intestines. The population of acidophilic granulocyte in the probiotic group was significantly higher at the proximal and distal parts when compared with the control group. The higher serum complement activity as well as the enhanced phagocytosis and killing ability of the head kidney leukocytes in the probiotic supplemented fish corresponded with the higher level of TNF alpha and IL-1 gene expression, suggesting that the induction of IL-1 and TNF alpha cytokines by
L. rhamnosus served as an important regulator of gut associated immune systems.
We present a simple strategy for the fabrication of porous carbon nanofibers (see figure). This procedure produces thin webs by electrospinning a polymer solution containing different concentrations ...of zinc chloride and subsequently thermally treating the system. Their resulting surface area and good electrical conductivity make these porous carbon nanofibers useful in the fabrication of efficient electrodes for supercapacitors.
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•Octahedral anatase particles (OAPs) modified with silver NPs by photodeposition.•Ag/OAPs with enhanced photocatalytic activity under both UV and vis irradiation.•Electron traps as ...nucleation sites for silver NPs.•Polydispersity of silver NPs results in broad LSPR and thus enhanced vis activity.•TRMC data correlate with photocatalytic activity.
Octahedral anatase particles (OAPs) were modified with silver nanoparticles (NPs) by photodeposition method. The properties of OAPs influenced the properties of silver deposits, and thus the photocatalytic activity of the obtained silver-modified OAPs. Photocatalytic activities were tested under UV and vis irradiation for oxidative decomposition of acetic acid and oxidation of 2-propanol, respectively. The properties of silver-modified OAPs were investigated by XRD, STEM, DRS, XPS and time-resolved microwave conductivity (TRMC) method. It was found that electron traps (ETs) worked as nucleation sites for silver, resulting in formation of smaller silver NPs on smaller OAPs with larger content of ETs. The modification with silver resulted in enhanced photocatalytic activity under both UV and vis irradiation. It was found that larger crystallite size of silver NPs, and thus larger polydispersity of silver deposits resulted in broad and intense plasmon resonance peak causing enhanced visible activity. The correlation between photocatalytic activity and TRMC data, e.g., slower decay of TRMC signal for more active samples, allowed discussion on property-governed photocatalytic activities of silver-modified titania.
Notch signaling is often and aberrantly activated by hypoxia during tumor progression; however, the exact pathological role of hypoxia-induced Notch signaling in tumor metastasis is as yet poorly ...understood. In this study, we aimed to define the mechanism of Notch-ligand activation by hypoxia in both primary tumor and bone stromal cells in the metastatic niche and to clarify their roles in tumor progression. We have analyzed the expression profiles of various Notch ligands in 779 breast cancer patients in GEO database and found that the expression of Jagged2 among all five ligands is most significantly correlated with the overall- and metastasis-free survival of breast cancer patients. The results of our immunohistochemical (IHC) analysis for Jagged2 in 61 clinical samples also revealed that both Jagged2 and Notch signaling were strongly upregulated at the hypoxic invasive front. Activation of Jagged2 by hypoxia in tumor cells induced EMT and also promoted cell survival in vitro. Notably, a γ-secretase inhibitor significantly blocked Notch-mediated invasion and survival under hypoxia by promoting expression of E-cadherin and inhibiting Akt phosphorylation. Importantly, Jagged2 was also found to be upregulated in bone marrow stroma under hypoxia and promoted the growth of cancer stem-like cells by activating their Notch signaling. Therefore, hypoxia-induced Jagged2 activation in both tumor invasive front and normal bone stroma has a critical role in tumor progression and metastasis, and Jagged2 is considered to be a valuable prognostic marker and may serve as a novel therapeutic target for metastatic breast cancer.
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