Neural processing of itch

A macroscopic ductile fracture criterion is proposed based on micro-mechanism analysis of nucleation, growth and shear coalescence of voids from experimental observation of fracture surfaces. The proposed ductile fracture model endows a changeable cut-off value for the stress triaxiality to represent effect of micro-structures, the Lode parameter, temperature, and strain rate on ductility of metals. The proposed model is used to construct fracture loci of AA 2024-T351. The constructed fracture loci are compared with experimental data covering wide stress triaxiality ranging between −0.5 and 1.0. The comparison suggests that the proposed model can provide a satisfactory prediction of ductile fracture for metals from compressive upsetting tests to plane strain tension with slanted fracture surfaces. Moreover, it is expected that the proposed model reasonably describes ductile fracture behavior in high velocity perforation simulation since a reasonable cut-off value for the stress triaxiality is coupled with the proposed ductile fracture criterion.

Modeling of shear ductile fracture considering a changeable cut-off value for stress triaxiality

The seven-transmembrane G protein-coupled receptors activated by leukotrienes are divided into two subclasses based on their ligand specificity for either leukotriene B4 or the cysteinyl leukotrienes (LTC4, LTD4, and LTE4). These receptors have been designated BLT and CysLT receptors, respectively, and a subdivision into BLT1 and BLT2 receptors and CysLT1 and CysLT2 receptors has been established. However, recent findings have also indicated the existence of putative additional leukotriene receptor subtypes. Furthermore, other ligands interact with the leukotriene receptors. Finally, leukotrienes may also activate other receptor classes, such as purinergic receptors. The aim of this review is to provide an update on the pharmacology, expression patterns, and pathophysiological roles of the leukotriene receptors as well as the therapeutic developments in this area of research.

https://pharmrev.aspetjournals.org/content/pharmrev/63/3/539.full.pdf

International Union of Basic and Clinical Pharmacology. LXXXIV: Leukotriene Receptor Nomenclature, Distribution, and Pathophysiological Functions

Eicosanoids are biologically active lipids in both physiologic and pathophysiologic situations. These mediators rapidly generate at sites of inflammation and act through specific receptors that following the generation of a signal transduction cascade, lead to coordinated cellular responses to specific stimuli. Prostanoids, that is, prostaglandins and thromboxane A(2), are active products of the cyclooxygenase pathway, while leukotrienes and lipoxins derive from the lipoxygenase pathway. In addition, a complex family of prostaglandin isomers called isoprostanes is derived as free-radical products of oxidative metabolism. While there is a wide consensus on the importance of the balance between proaggregating (thromboxane A(2)) and antiaggregating (prostacyclin) cyclooxygenase products in cardiovascular homeostasis, an increasing body of evidence suggests a key role also for other eicosanoids generated by lipoxygenases, epoxygenases, and nonenzymatic pathways in cardiovascular diseases. This intricate network of lipid mediators is unique considering that from a single precursor, arachidonic acid, may derive an array of bioproducts that interact within each other synergizing or, more often, behaving as functional antagonists.

Eicosanoids and their drugs in cardiovascular diseases: focus on atherosclerosis and stroke.

In this paper, we propose a new memristorbased crossbar array architecture, where a single memristor array and constant-term circuit are used to represent both plus-polarity and minus-polarity matrices This is different from the previous crossbar array architecture which has two memristor arrays to represent plus-polarity and minus-polarity connection matrices, respectively The proposed crossbar architecture is tested and verified to have the same performance with the previous crossbar architecture for applications of character recognition For areal density, however, the proposed crossbar architecture is twice better than the previous architecture, because only single memristor array is used instead of two crossbar arrays Moreover, the power consumption of the proposed architecture can be smaller by 48% than the previous one because the number of memristors in the proposed crossbar architecture is reduced to half compared to the previous crossbar architecture From the high areal density and high energy efficiency, we can know that this newly proposed crossbar array architecture is very suitable to various applications of analog neuromorphic computing that demand high areal density and low energy consumption

New Memristor-Based Crossbar Array Architecture with 50-% Area Reduction and 48-% Power Saving for Matrix-Vector Multiplication of Analog Neuromorphic Computing

Simulation of ship collision and grounding damage using Hosford-Coulomb fracture model for shell elements

Background and purpose:

Recently, we reported that 12(S)-HPETE (12(S)-hydroperoxyeicosa-5Z,8Z,10E,14Z-tetraenoic acid) induces scratching in ICR mice. We hypothesized that 12(S)-HPETE might act as an agonist of the low-affinity leukotriene B4 receptor BLT2. To confirm the involvement of the BLT2 receptor in 12(S)-HPETE-induced scratching, we studied the scratch response using the BLT2 receptor agonists compound A (4′-{[pentanoyl (phenyl) amino]methyl}-1,1′-biphenyl-2-carboxylic acid) and 12(S)-HETE (12(S)-hydroxyeicosa-5Z,8Z,10E,14Z-tetraenoic acid).



Experimental approach:

A video recording was used to determine whether the BLT2 receptor agonists caused itch-associated scratching in ICR mice. Selective antagonists and several chemicals were used.



Key results:

Both 12(S)-HETE and compound A dose dependently induced scratching in the ICR mice. The dose–response curve for compound A showed peaks at around 0.005–0.015 nmol per site. Compound A- and 12(S)-HETE-induced scratching was suppressed by capsaicin and naltrexon. We examined the suppressive effects of U75302 (6-[6-(3-hydroxy-1E,5Z-undecadienyl)-2-pyridinyl]-1,5-hexanediol, the BLT1 receptor antagonist) and LY255283 (1-[5-ethyl-2-hydroxy-4-[[6-methyl-6-(1H-tetrazol-5-yl)heptyl]oxy]phenyl]-ethanone, the BLT2 receptor antagonist) on the BLT2 agonist-induced scratching. LY255283 suppressed compound A- and 12(S)-HETE-induced scratching, but U75302 did not. LY255283 required a higher dose to suppress the compound A-induced scratching than it did to suppress the 12(S)-HETE-induced scratching. One of the BLT2 receptor agonists, 12(R)-HETE (12(R)-hydroxyeicosa-5Z,8Z,10E,14Z-tetraenoic acid), also induced scratching in the ICR mice.



Conclusions and implications:

Our present results corroborate the hypothesis that the BLT2 receptor is involved in 12(S)-lipoxygenase-product-induced scratching in ICR mice. We also confirmed that this animal model could be a valuable means of evaluating the effects of BLT2 receptor antagonists.



British Journal of Pharmacology (2008) 154, 1073–1078; doi:10.1038/bjp.2008.220; published online 9 June 2008

/pdf/involvement-of-the-blt2-receptor-in-the-itch-associated-xn3thuzoxm.pdf

Involvement of the BLT2 receptor in the itch-associated scratching induced by 12-(S)-lipoxygenase products in ICR mice

To predict ductile fracture initiation of EH36 grade high tensile strength steels, the Hosford–Coulomb ductile fracture model was employed. The ductile fracture tests were carried out on different ...

Ductile fracture prediction of EH36 grade steel based on Hosford–Coulomb model

Modeling, testing and calibration of ductile crack formation in grade DH36 ship plates

Accidental events such as collision, grounding, and explosion in marine structures can cause plastic deformation and structural damage. Various fracture models based on different mechanical concept...

Sung-Ju Park

Papers

Simulation of ship collision and grounding damage using Hosford-Coulomb fracture model for shell elements

Involvement of the BLT2 receptor in the itch-associated scratching induced by 12-(S)-lipoxygenase products in ICR mice

Ductile fracture prediction of EH36 grade steel based on Hosford–Coulomb model

Modeling, testing and calibration of ductile crack formation in grade DH36 ship plates

Comparative study on ductile fracture prediction of high-tensile strength marine structural steels