Precise knowledge of the fundamental properties of the proton is essential for our understanding of atomic structure as well as for precise tests of fundamental symmetries. We report on a direct ...high-precision measurement of the magnetic moment μp of the proton in units of the nuclear magneton μN. The result, μp = 2.79284734462 (±0.00000000082) μN, has a fractional precision of 0.3 parts per billion, improves the previous best measurement by a factor of 11, and is consistent with the currently accepted value. This was achieved with the use of an optimized double–Penning trap technique. Provided a similar measurement of the antiproton magnetic moment can be performed, this result will enable a test of the fundamental symmetry between matter and antimatter in the baryonic sector at the 10−10 level.
We used cold atmospheric pressure plasma jet to examine in detail 1O2 generation in water. ESR with 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide, a secondary amine probe, was used for the detection ...of 1O2. Nitroxide radical formation was detected after cold atmospheric pressure plasma jet irradiation of a 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide solution. An 1O2 scavenger/quencher inhibited the ESR signal intensity induced by cold atmospheric pressure plasma jet irradiation, but this inhibition was not 100%. As 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide reacts with oxidizing species other than 1O2, it was assumed that the signal intensity inhibited by NaN3 corresponds to only the nitroxide radical generated by 1O2. The concentration of 1O2 produced by cold atmospheric pressure plasma jet irradiation for 60 s was estimated at 8 μM. When this 1O2 generation was compared to methods of 1O2 generation like rose bengal photoirradiation and 4-methyl-1,4-etheno-2,3-benzodioxin-1(4H)-propanoic acid (endoperoxide) thermal decomposition, 1O2 generation was found to be, in decreasing order, rose bengal photoirradiation ≥ cold atmospheric pressure plasma jet > endoperoxide thermal decomposition. Cold atmospheric pressure plasma jet is presumed to not specifically generate 1O2, but can be used to mimic states of oxidative stress involving multiple ROS.
Francium (Fr), which is the alkali atom in the 7th period, can be obtained as ultracold atoms with laser cooling and trapping techniques, and could be employed for the experiments on searches for the ...permanent electric dipole moment (EDM) of an electron. In order to improve the sensitivity of the electron EDM search, development of a high-intensity source of Fr atoms is essential. We demonstrated a production of a high intensity
210
Fr ion beam with a rate of
5
×
10
6
ions/s by a fusion reaction with bombardment of an accelerated
18
O beam onto a fixed gold target in RIKEN. The Fr products inside the gold target were extracted from the gold surface as an ion beam focused with an electrostatic field. We also discussed the method to produce
221
Fr by
α
-decay of
225
Ac. A neutron-rich
221
Fr isotope can be obtained as a daughter nucleus of this decay.
The circadian peripheral clock is entrained by restricted feeding (RF) at a fixed time of day, and insulin secretion regulates RF-induced entrainment of the peripheral clock in mice. Thus, ...carbohydrate-rich food may be ideal for facilitating RF-induced entrainment, although the role of dietary oils in insulin secretion and RF-induced entrainment has not been described. The soybean oil component of standard mouse chow was substituted with fish or soybean oil containing docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA). Tuna oil (high DHA/EPA), menhaden oil (standard), and DHA/EPA dissolved in soybean oil increased insulin secretion and facilitated RF-induced phase shifts of the liver clock as represented by the bioluminescence rhythms of PER2::LUCIFERASE knock-in mice. In this model, insulin depletion blocked the effect of tuna oil and fish oil had no effect on mice deficient for GPR120, a polyunsaturated fatty acid receptor. These results suggest food containing fish oil or DHA/EPA is ideal for adjusting the peripheral clock.
Although the circadian liver clock is entrained by the feeding cycle, factors such as food volume and starvation interval are poorly understood. Per2::Luc knock-in mice were given two meals per day ...with different food volume sizes and/or with different intervals of starvation between two mealtimes with the total food volume per day fixed at 3.6 g (80 food pellets, ∼75% of free feeding) per mouse. The bioluminescence rhythm in the liver produced a unimodal peak but not bimodal peak under the regimen of two meals per day over 14-15 days. Peak Per2 expression occurred concurrently with the mealtime of the larger food volume, when the first and second meal were given as different food volume ratios under a 12 h feeding interval. When an equal volume of food was given under different starvation interval (8 h:16 h), the peak of the Per2 rhythm was close to peak by mealtime after long starvation (16 h). When food volumes for each mealtime were changed under 8 h:16 h, the peak rhythm was influenced by combined factors of food volume and starvation interval. Food intake after the 16-h starvation caused a significant increase in liver Per2, Dec1, and Bmal1 gene expression compared with food intake after the 8-h starvation with 8 h:16 h feeding intervals. In conclusion, the present results clearly demonstrate that food-induced entrainment of the liver clock is dependent on both food volume and the starvation interval between two meals. Therefore, normal feeding habits may help to maintain normal clock function in the liver organ.
Abstract Restricting feeding to daytime can entrain circadian clocks in peripheral organs of rodents, and nutrients that rapidly increase the blood glucose level are suitable for inducing ...entrainment. However, dietetic issues, for example, whether or not the diet comprises heated food, have not been fully explored. We therefore hypothesized that rapidly digested starch causes stronger entrainment than slowly digested starch. The entrainment ability of the liver clock in PER2::LUCIFERASE knock-in mice, blood glucose levels, insulin levels, and acute changes in liver clock gene expression were compared between a β -starch (native)–substituted AIN-93M standard diet and an α -starch (gelatinized)–substituted diet. β -Corn and β -rice starch induced larger phase delays of the liver clock, larger blood glucose increases, and higher Per2 gene expression in the liver compared with β -potato starch. Starch granule size, as examined by electron microscopy, was larger for β -potato starch than for β -corn or β -rice starch. After heating, we obtained gelatinized α -potato, α -corn, and α -rice starch, which showed destruction of the crystal structure and a high level of gelatinization. No difference in the increase of blood glucose or insulin levels was observed between β -corn and α -corn starch, or between β -rice and α -rice starch. In contrast, α -potato starch caused higher levels of glucose and insulin compared with β -potato starch. An α -potato starch–substituted diet induced larger phase delays of the liver clock than did β -potato starch. Therefore, rapidly digested starch is appropriate for peripheral clock entrainment. Dietetic issues (heated vs unheated) are important when applying basic mouse data to humans.
We used cold atmospheric pressure plasma jet to examine in detail 1O2 generation in water. ESR with 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide, a secondary amine probe, was used for the detection ...of 1O2. Nitroxide radical formation was detected after cold atmospheric pressure plasma jet irradiation of a 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide solution. An 1O2 scavenger/quencher inhibited the ESR signal intensity induced by cold atmospheric pressure plasma jet irradiation, but this inhibition was not 100%. As 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide reacts with oxidizing species other than 1O2, it was assumed that the signal intensity inhibited by NaN3 corresponds to only the nitroxide radical generated by 1O2. The concentration of 1O2 produced by cold atmospheric pressure plasma jet irradiation for 60 s was estimated at 8 μM. When this 1O2 generation was compared to methods of 1O2 generation like rose bengal photoirradiation and 4-methyl-1,4-etheno-2,3-benzodioxin-1(4H)-propanoic acid (endoperoxide) thermal decomposition, 1O2 generation was found to be, in decreasing order, rose bengal photoirradiation ≥ cold atmospheric pressure plasma jet > endoperoxide thermal decomposition. Cold atmospheric pressure plasma jet is presumed to not specifically generate 1O2, but can be used to mimic states of oxidative stress involving multiple ROS.
A reservoir trap for antiprotons Smorra, C.; Mooser, A.; Franke, K. ...
International journal of mass spectrometry,
10/2015, Letnik:
389
Journal Article
Recenzirano
Odprti dostop
Display omitted
•A reservoir trap for antiprotons or for other exotic particles has been developed.•We implemented a novel scheme for single particle extraction from the reservoir.•The extraction ...scheme is reversible and without particle loss.•In this trap we achieve antiproton storage times of more than 1 year.•This enables antiproton precision measurements independent from accelerator cycles.
We have developed techniques to extract arbitrary fractions of antiprotons from an accumulated reservoir, and to inject them into a Penning-trap system for high-precision measurements. In our trap-system antiproton storage times >1.08 years are estimated. The device is fail-safe against power-cuts of up to 10h. This makes our planned comparisons of the fundamental properties of protons and antiprotons independent from accelerator cycles, and will enable us to perform experiments during long accelerator shutdown periods when background magnetic noise is low. The demonstrated scheme has the potential to be applied in many other precision Penning trap experiments dealing with exotic particles.
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