Lipopolysaccharide (LPS) suppresses follicle development marker expression and enhances cytokine expressions, which results in fail to granulosa cell proliferation in developing follicle in cows.

Postpartum endometritis is known to be associated with ovarian dysfunction in cows. Lipopolysaccharide (LPS) generated by Gram-negative bacteria is recognized by toll-like receptor 4 (TLR4), which leads to an inflammatory response by the generation of cytokines such as tumor necrosis factor-α (TNF-α) and interleukins. In this study, we investigated the effect of endometrial LPS on granulosa cell functions during early follicular development in cows. Uteri and follicles were obtained from a slaughterhouse and classified into either clinical endometritis (CE) or normal groups by vaginal mucus test. TLR4 mRNA and protein in normal cows were expressed in granulosa cells collected from follicles measuring 1-3 and 4-7 mm in a diameter, respectively. LPS content in endometrium and follicular fluid of CE cows was significantly higher than that in normal cows. Compared to normal cows, CE cows showed lower expression of follicular development markers (FSHR, CYP19A1, CCND2, and LHCGR) in granulosa cells, lower estradiol-17ß concentrations in follicular fluid, and lower granulosa cell proliferation. CE contraction significantly increased cytokine expressions (TNF, IL-1A, and IL-1B) in granulosa cells and suppressed apoptosis of granulosa cells compared to normal cows. LPS significantly suppressed the expression of follicular development markers and the production of estradiol-17ß in granulosa cells and reduced granulosa cells proliferation compared to cells cultured without LPS. LPS significantly increased cytokine expressions and suppressed granulosa cell apoptosis. Thus, the present results suggest that the existence of LPS in developing follicles is one of the causes of ovarian quiescence in cows.

Spectrally blue hydrated parent body of asteroid (162173) Ryugu.

Ryugu is a carbonaceous rubble-pile asteroid visited by the Hayabusa2 spacecraft. Small rubble pile asteroids record the thermal evolution of their much larger parent bodies. However, recent space weathering and/or solar heating create ambiguities between the uppermost layer observable by remote-sensing and the pristine material from the parent body. Hayabusa2 remote-sensing observations find that on the asteroid (162173) Ryugu both north and south pole regions preserve the material least processed by space weathering, which is spectrally blue carbonaceous chondritic material with a 0-3% deep 0.7-µm band absorption, indicative of Fe-bearing phyllosilicates. Here we report that spectrally blue Ryugu's parent body experienced intensive aqueous alteration and subsequent thermal metamorphism at 570-670 K (300-400 °C), suggesting that Ryugu's parent body was heated by radioactive decay of short-lived radionuclides possibly because of its early formation 2-2.5 Ma. The samples being brought to Earth by Hayabusa2 will give us our first insights into this epoch in solar system history.

Quantitative Potassium Measurements with Laser-Induced Breakdown Spectroscopy Using Low-Energy Lasers: Application to In Situ K-Ar Geochronology for Planetary Exploration.

In situ radiogenic isotope measurements to obtain the absolute age of geologic events on planets are of great scientific value. In particular, K-Ar isochrons are useful because of their relatively high technical readiness and high accuracy. Because this isochron method involves spot-by-spot K measurements using laser-induced breakdown spectroscopy (LIBS) and simultaneous Ar measurements with mass spectrometry, LIBS measurements are conducted under a high vacuum condition in which emission intensity decreases significantly. Furthermore, using a laser power used in previous planetary missions is preferable to examine the technical feasibility of this approach. However, there have been few LIBS measurements for K under such conditions. In this study, we measured K contents in rock samples using 30 mJ and 15 mJ energy lasers under a vacuum condition (10-3 Pa) to assess the feasibility of in situ K-Ar dating with lasers comparable to those used in NASA's Curiosity and Mars 2020 missions. We obtained various calibration curves for K using internal normalization with the oxygen line at 777 nm and continuum emission from the laser-induced plasma. Experimental results indicate that when K2O < 1.1 wt%, a calibration curve using the intensity of the K emission line at 769 nm normalized with that of the oxygen line yields the best results for the 30 mJ laser energy, with a detection limit of 88 ppm and 20% of error at 2400 ppm of K2O. Futhermore, the calibration curve based on the K 769 nm line intensity normalized with continuum emission yielded the best result for the 15 mJ laser, giving a detection limit of 140 ppm and 20% error at 3400 ppm K2O. Error assessments using obtained calibration models indicate that a 4 Ga rock with 3000 ppm K2O would be measured with 8% (30 mJ) and 10% (15 mJ) of precision in age when combined with mass spectrometry of 40Ar with 10% of uncertainty. These results strongly suggest that high precision in situ isochron K-Ar dating is feasible with a laser used in previous and upcoming Mars rover missions.