Axionlike-particle generation by laser-plasma interaction

Axion, a hypothetical particle that is crucial to quantum chromodynamics and dark matter theory, has not yet been found in any experiment. With the improvement of laser technique, much stronger quasi-static electric and magnetic fields can be created in laboratory using laser-plasma interaction. In this article, we discuss the feasibility of axion or axionlike-particle's exploring experiments using planar and cylindrically symmetric laser-plasma fields as backgrounds while probing with an ultrafast superstrong optical laser or x-ray free-electron laser with high photon number. Compared to classical magnet design, the axion source in laser-plasma interaction trades the accumulating length for the source's interacting strength. Besides, a structured field in the plasma creates a tunable transverse profile of the interaction and improves the signal-noise ratio via the mechanisms such as phase-matching. The mass of axion discussed in this article ranges from 1 \textmu eV to 1 eV. Some simple schemes and estimations of axion production and probe's polarization rotation are given, which reveals the possibility of future laser-plasma axion source in laboratory.Comment: 24 pages, 5 figure

The efficiency of ultrasound-guided erector spinae plane block in early cervical cancer patients undergoing laparotomic radical hysterectomy: A double-blind randomized controlled trial

AimsWe aim to compare the efficiency of erector spinae plane block (ESPB) with transversus abdominis plane block (TAPB) in patients undergoing laparotomic radical hysterectomy because only a few studies are reported exploring this matter.MethodsIn this randomized controlled trail, 154 eligible patients were randomly allocated into ESPB group [ESPB + patient-controlled intravenous analgesia (PCIA)] and TAPB group (TAPB + PCIA) at 1:1 ratio. The primary outcome was visual analog scale (VAS) score at rest state at 12 h.ResultsWe found that ESPB group was associated with the lower VAS scores at rest and cough state than TAPB group at 2, 4, 6, 12, and 24 h postoperatively (P < 0.05). Less analgesic consumption and sufentanil consumption in PCIA pump were found in the ESPB group (P < 0.05). Moreover, ESPB group was followed by fewer rescue analgesia requirements, less rescue analgesic consumption, less adverse reactions, and higher analgesia satisfaction (P < 0.05).ConclusionsOur study found that ESPB had advantages on analgesic effect and opioids consumption. In the future, more studies were needed to confirm our findings. Systematic Review Registration:https://www.chictr.org.cn/index.aspx, identifier: ChiCTR2100044240

Peonidin-3-O-Glucoside from Purple Corncob Ameliorates Nonalcoholic Fatty Liver Disease by Regulating Mitochondrial and Lysosome Functions to Reduce Oxidative Stress and Inflammation

A frequent chronic liver condition across the world is nonalcoholic fatty liver disease (NAFLD). Oxidative stress caused by lipid accumulation is generally considered to be the main cause of NAFLD. Anthocyanins can effectively inhibit the production of reactive oxygen species and improve oxidative stress. In this work, six major anthocyanins were separated from purple corncob by semi-preparative liquid chromatography. The effects of the 6 kinds of anthocyanins against NAFLD were investigated using a free fatty acid (FFA)-induced cell model. The results showed that peonidin 3-O-glucoside (P3G) can significantly reduce lipid accumulation in the NAFLD cell model. The treatment with P3G also inhibited oxidative stress via inhibiting the excessive production of reactive oxygen species and superoxide anion, increasing glutathione levels, and enhancing the activities of SOD, GPX, and CAT. Further studies unveiled that treatment with P3G not only alleviated inflammation but also improved the depletion of mitochondrial content and damage of the mitochondrial electron transfer chain developed concomitantly in the cell model. P3G upregulated transcription factor EB (TFEB)-mediated lysosomal function and activated the peroxisome proliferator-activated receptor alpha (PPARα)-mediated peroxisomal lipid oxidation by interacting with PPARα possibly. Overall, this study added to our understanding of the protective effects of purple corn anthocyanins against NAFLD and offered suggestions for developing functional foods containing these anthocyanins

Extraction optimization and structural characterization of soluble dietary fiber in foxtail millet and its inhibitory activities on colon cancer

Soluble dietary fiber has anti-tumor effect and is closely related to human health. At present the structure of soluble dietary fiber from foxtail millet (FMB-SDF) and its anti-tumor effect remain unclear. In this study, the structure of FMB-SDF was characterized, and its effects on the colon cancer were investigated. The results showed that under optimal extraction conditions the yield of FMB-SDF was 14.25 %. Based on the monosaccharide composition, methylation results and NMR analysis, the preliminary structure of FMB-SDF was inferred to be a glucan. Interestingly, FMB-SDF markedly inhibited the colony formation ability of HCT116 and HT-29 cells and could significantly induce the increase of reactive oxygen species (ROS) and apoptosis of HCT116 and HT-29 cells. The results of animal experiments showed that FMB-SDF could significantly alleviate clinical symptoms of colon cancer in mice. These results provide a theoretical basis for the exploitation and utilization of FMB-SDF against colon cancer

Modulation Of Human 5-Lipoxygenase Activity By Membrane Lipids

Mammalian 5-lipoxygenase (5-LO) catalyzes the conversion of arachidonic acid (AA) to leukotrienes, potent inflammatory mediators. 5-LO is activated by a Ca2+-mediated translocation to membranes, and demonstrates the characteristic features of interfacially activated enzymes, yet the mechanism of membrane binding of 5-LO is not well understood. In an attempt to understand the mechanism of lipid-mediated activation of 5-LO, we have studied the effects of a large set of lipids on human recombinant 5-LO activity, as well as mutual structural effects of 5-LO and membranes. In the presence of 0.35 mM phosphatidylcholine (PC) and 0.2 mM Ca2+, there was substrate inhibition at \u3e100 μM AA. Data analysis at low AA concentrations yielded the following: Km ≈ 103 μM and kcat ≈ 56 s -1. 5-LO activity was supported by PC more than by any other lipid tested except for a cationic lipid, which was more stimulatory than PC. Binding of 5-LO to zwitterionic and acidic membranes was relatively weak; the extent of binding increased 4-8 times in the presence of Ca2+, whereas binding to cationic membranes was stronger and essentially Ca2+-independent. Polarized attenuated total reflection infrared experiments implied that 5-LO binds to membranes at a defined orientation with the symmetry axis of the putative N-terminal β-barrel tilted ∼45° from the membrane normal. Furthermore, membrane binding of 5-LO resulted in dehydration of the membrane surface and was paralleled with stabilization of the structures of both 5-LO and the membrane. Our results provide insight into the understanding of the effects of membrane surface properties on 5-LO - membrane interactions and the interfacial activation of 5-LO

Structural And Functional Effects Of Tryptophans Inserted Into The Membrane-Binding And Substrate-Binding Sites Of Human Group Iia Phospholipase A2

Phospholipase A2 (PLA2) enzymes become activated by binding to biological membranes and hydrolyze phospholipids to free fatty acids and lyso-phospholipids, the precursors of inflammatory mediators. To understand the functional significance of amino acid residues at key positions, we have studied the effects of the substitution of Val3 (membrane binding surface) and Phe5 (substrate binding pocket) of human group IIA PLA2 by tryptophan on the structure and function of the enzyme. Despite the close proximity of the sites of mutations, the V3W mutation results in substantial enhancement of the enzyme activity, whereas the F5W mutant demonstrates significantly suppressed activity. A structural analysis of all three proteins free in buffer and bound to membranes indicates that large differences in activities result from distinct conformational changes in PLA2s upon membrane binding. Although PLA2 and the V3W mutant demonstrate a decrease in helical content and an increase in helix flexibility, the F5W mutant experiences partial distortion of the α-helical structure presumably resulting from the tendency of Trp 5 to insert into the membrane. Furthermore, whereas the PLA 2 and the V3W mutant bind to the membrane at similar and apparently productive-mode orientation, the F5W mutant binds to membranes with a distinctly different orientation. It is suggested that both the stimulatory effect of the V3 W mutation and the inhibitory effect of the F5W mutation result from the high affinity of Trp for the membrane-water interface. Although Trp3 at the membrane binding face of PLA2 facilitates the proper membrane binding of the enzyme, Trp5 in the internal substrate binding site causes partial unwinding of the N-terminal helix in order to interact with the membrane. © 2006 American Chemical Society

Antioxidant potential of styrene pyrone polyphenols from Inonotus obliquus: A combined experimental, density functional theory (DFT) approach and molecular dynamic (MD) simulation

Polyphenols containing styrene pyranone skeleton are unique to porous fungi. Inonotus obliquus (IO) is a medicinal and edible porous fungus. Twelve phenolic compounds containing four styryl pyranone polyphenols from IO were isolated and identified in this work. The antioxidant ability of the isolates was characterized utilizing the ferric reducing antioxidant power (FRAP) assay and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging test. Styrylpyranone polyphenols, especially methylinoscavin B, could capture free radicals better than other phenolic compounds, and quantum chemical calculations also confirmed this evaluation. The density functional theory (DFT) calculation data showed that Styrylpyranone polyphenols, especially methylinoscavin B, have a lower energy gap, higher softness and higher electronic chemical potential than other phenolic compounds. The bond dissociation energy values of the bond in C7ʹ O–H of the methylinoscavin B molecule are less than those in C11 and C6ʹ O–H when reacting with ∙OOH (selected as a representative free radical). On the basis of calculations, hydrogen atom transfer (HAT) is supposed to be a preferred mechanism over single electron transfer (SET) when phenolic compounds react with free radicals. Moreover, after treatment with final concentrations of 0.5, 1, 2, 3, 4 and 5 μM phelligridin E (PHE), the activity of SOD1 increased by 70.15%, 11.36%, 145.45%, 172.73%, 205.05% and 275.23%, respectively. The molecular dynamics simulation (MD) study of PHE employed SOD1 (PDB ID: 6FN8). The MD results showed that the hydrogen bonds between ASP147 of SOD1 and PHE promote GLU223-ARG224 to form a stable C coil after combining with PHE. The formation of the C Coil enhanced the stability of the electrostatic loop (EL) of SOD1 and the rate of diffusion of the superoxide anion to the active site. Styrylpyrone polyphenols of Inonotus obliquus origin have the potential to be a source of vigorous free radical scavengers and antioxidant enzyme activators

J. Wuhan Univ. Technol.-Mat. Sci. Edit.

A kind of ceramic slurry was prepared and sprayed onto the surface of 9Ni steel at room temperature. The coating layer will not only reduce the depth of the formed Ni-enriched entanglement at high temperature but also have an excellent ability to resist oxidation of the 9Ni steel. Compared to bare specimen, the depths of the entanglement of the coated 9Ni specimen could be successfully reduced by 74.1% and the oxidation loss be decreased by 62.3% by heating at 1 250 degrees C for 60min. In addition, the coated specimen indicates no trace of oxide pegs. It proves that the coating has outstanding improvement to internal oxidation resistance. Some characterization methods such as metalloscopy, XRD, XPS, SEM and EDX have been used to reveal a possible protective mechanism. The result shows that the coating layer reacts with the iron oxide to form MgFe2O4 on the surface of the coated specimen, which could provide a smaller diffusion coefficient rate of Fe ion. The coating with a low cost and easy implementation is promisingly applicable in the slab-reheating process of the 9Ni steel.A kind of ceramic slurry was prepared and sprayed onto the surface of 9Ni steel at room temperature. The coating layer will not only reduce the depth of the formed Ni-enriched entanglement at high temperature but also have an excellent ability to resist oxidation of the 9Ni steel. Compared to bare specimen, the depths of the entanglement of the coated 9Ni specimen could be successfully reduced by 74.1% and the oxidation loss be decreased by 62.3% by heating at 1 250 degrees C for 60min. In addition, the coated specimen indicates no trace of oxide pegs. It proves that the coating has outstanding improvement to internal oxidation resistance. Some characterization methods such as metalloscopy, XRD, XPS, SEM and EDX have been used to reveal a possible protective mechanism. The result shows that the coating layer reacts with the iron oxide to form MgFe2O4 on the surface of the coated specimen, which could provide a smaller diffusion coefficient rate of Fe ion. The coating with a low cost and easy implementation is promisingly applicable in the slab-reheating process of the 9Ni steel