The reaction of forsterite with hydrogen-its apparent and real temperature dependences

We have studied experimentally the reaction rate between solid forsterite and hydrogen gas, one of the most fundamental reactions in the solar nebula. It was found that the rate-controlling gas species was atomic hydrogen rather than molecular hydrogen, from the linear dependence of the reaction rate on P_H. The temperature dependence of the reaction rate was determined both under constant P_ and under constant P_H conditions. The former, "apparent" activation energy of the reaction was estimated to be 86.5±4.8 (2σ)kcal/mol. The latter, "real" activation energy was estimated to be 32.6±4.8 (2σ)kcal/mol. From this, a general formula that gives the true reaction rate of forsterite with hydrogen was obtained : log_(J_F/g cm^s^)=-32.6(±4.8)×10^3/2.303 RT+log_(P_H/atm)+4.00(±0.07)

Proteolytic release of the carboxy-terminal fragment of proHB-EGF causes nuclear export of PLZF

Cleavage of membrane-anchored heparin-binding EGF-like growth factor (proHB-EGF) via metalloprotease activation yields amino- and carboxy-terminal regions (HB-EGF and HB-EGF-C, respectively), with HB-EGF widely recognized as a key element of epidermal growth factor receptor transactivation in G protein–coupled receptor signaling. Here, we show a biological role of HB-EGF-C in cells. Subsequent to proteolytic cleavage of proHB-EGF, HB-EGF-C translocated from the plasma membrane into the nucleus. This translocation triggered nuclear export of the transcriptional repressor, promyelocytic leukemia zinc finger (PLZF), which we identify as an HB-EGF-C binding protein. Suppression of cyclin A and delayed entry of S-phase in cells expressing PLZF were reversed by the production of HB-EGF-C. These results indicate that released HB-EGF-C functions as an intracellular signal and coordinates cell cycle progression with HB-EGF

Effectiveness of mHealth consultation services for preventing postpartum depressive symptoms: a randomized clinical trial

妊娠中・産後にオンライン健康医療相談が利用できることで産後うつリスクが3分の2に低下. 京都大学プレスリリース. 2023-08-03.[Background] Although many conventional healthcare services to prevent postpartum depression are provided face-to-face, physical and psychosocial barriers remain. These barriers may be overcome by using mobile health services (mHealth). To examine the effectiveness of mHealth professional consultation services in preventing postpartum depressive symptoms in real-world settings, we conducted this randomized controlled trial in Japan, where universal free face-to-face perinatal care is available. [Methods] This study included 734 pregnant women living in Yokohama city who could communicate in Japanese, recruited at public offices and childcare support facilities. The participants were randomized to the mHealth group (intervention, n = 365), where they could use a free app-based mHealth consultation service with gynecologists/obstetricians, pediatricians, and midwives whenever and as many times as they wanted between 6 p.m. and 10 p.m. on weekdays throughout their pregnancy and postpartum periods (funded by the City of Yokohama government) or the usual care group (control, n = 369). The primary outcome was the risk of elevated postpartum depressive symptoms, defined as Edinburgh Postnatal Depression Scale score ≥ 9. Secondary outcomes were self-efficacy, loneliness, perceived barriers to healthcare access, number of clinic visits, and ambulance usage. All outcomes were collected three months post-delivery. We also conducted subgroup analyses assessing the differences in the treatment effect by sociodemographic status. [Results] Most women completed all questionnaires (n = 639 of 734, response rate: 87%). The mean baseline age was 32.9 ± 4.2 years, and 62% were primipara. Three months post-delivery, women in the mHealth group had a lower risk of elevated postpartum depressive symptoms (47/310 [15.2%]) compared to the usual care group (75/329 [22.8%], risk ratio: 0.67 [95% confidence interval: 0.48–0.93]). Compared with the usual care group, women in the mHealth group had higher self-efficacy, less loneliness, and fewer perceived barriers to healthcare access. No differences were observed in the frequency of clinic visits or ambulance usage. Furthermore, in the subgroup analyses, we did not find differences in the treatment effect by sociodemographic status. [Conclusions] Local government-funded mHealth consultation services have a preventive effect on postpartum depressive symptoms, removing physical and psychological barriers to healthcare access in real-world settings

Synthesis, Structures, and Luminescence Properties of Interconvertible Au^I_2Zn^II and Au^I_3Zn^II Complexes with Mixed Bis(diphenylphosphino)methane and D-Penicillaminate

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see　http://dx.doi.org/10.1021/ic402462

Three-flavor quark mass dependence of baryon spectra in holographic QCD

We introduce the strange quark mass to the Sakai-Sugimoto model of holographic QCD. We compute mass shifts in the spectra of three-flavor baryons at the leading order in perturbation in quark masses. Comparison with experimental data shows an agreement only qualitatively.Comment: 17 pages, v2: minor corrections, v3: published versio

Bacterial inducible expression of plant cell wall-binding protein YesO through conflict between Glycine max and saprophytic Bacillus subtilis

大豆と納豆菌のせめぎ合いの仕組みを解明 --生きた大豆は納豆菌を嫌い、納豆菌は死んだ大豆が好き--. 京都大学プレスリリース. 2020-11-02.Saprophytic bacteria and plants compete for limited nutrient sources. Bacillus subtilis grows well on steamed soybeans Glycine max to produce the fermented food, natto. Here we focus on bacterial responses in conflict between B. subtilis and G. max. B. subtilis cells maintained high growth rates specifically on non-germinating, dead soybean seeds. On the other hand, viable soybean seeds with germinating capability attenuated the initial growth of B. subtilis. Thus, B. subtilis cells may trigger saprophytic growth in response to the physiological status of G. max. Scanning electron microscope observation indicated that B. subtilis cells on steamed soybeans undergo morphological changes to form apertures, demonstrating cell remodeling during saprophytic growth. Further, transcriptomic analysis of B. subtilis revealed upregulation of the gene cluster, yesOPQR, in colonies growing on steamed soybeans. Recombinant YesO protein, a putative, solute-binding protein for the ATP-binding cassette transporter system, exhibited an affinity for pectin-derived oligosaccharide from plant cell wall. The crystal structure of YesO, in complex with the pectin oligosaccharide, was determined at 1.58 Å resolution. This study expands our knowledge of defensive and offensive strategies in interspecies competition, which may be promising targets for crop protection and fermented food production

Strategies to enhance the excitation energy-transfer efficiency in a light-harvesting system using the intra-molecular charge transfer character of carotenoids

Fucoxanthin is a carotenoid that is mainly found in light-harvesting complexes from brown algae and diatoms. Due to the presence of a carbonyl group attached to polyene chains in polar environments, excitation produces an excited intra-molecular charge transfer. This intra-molecular charge transfer state plays a key role in the highly efficient (∼95%) energy-transfer from fucoxanthin to chlorophyll a in the light-harvesting complexes from brown algae. In purple bacterial light-harvesting systems the efficiency of excitation energy-transfer from carotenoids to bacteriochlorophylls depends on the extent of conjugation of the carotenoids. In this study we were successful, for the first time, in incorporating fucoxanthin into a light-harvesting complex 1 from the purple photosynthetic bacterium, Rhodospirillum rubrum G9+ (a carotenoidless strain). Femtosecond pump-probe spectroscopy was applied to this reconstituted light-harvesting complex in order to determine the efficiency of excitation energy-transfer from fucoxanthin to bacteriochlorophyll a when they are bound to the light-harvesting 1 apo-proteins

Enhanced propagation of Granulicatella adiacens from human oral microbiota by hyaluronan

Host determinants for formation/composition of human oral microbiota remain to be clarified, although microorganisms entering the mouth cannot necessarily colonize the oral environment. Here we show that human oral-abundant bacteria degraded host glycosaminoglycans (GAGs) in saliva and gingiva, and certain bacteria significantly grew on hyaluronan (HA), a kind of GAGs. Microbial communities from teeth or gingiva of healthy donors assimilated HA. Metagenomic analysis of human oral microbiota under different carbon sources revealed HA-driven Granulicatella growth. HA-degrading bacterial strains independently isolated from teeth and gingiva were identified as Granulicatella adiacens producing extracellular 130 kDa polysaccharide lyase as a HA-degrading enzyme encoded in a peculiar GAG genetic cluster containing genes for isomerase KduI and dehydrogenase DhuD. These findings demonstrated that GAGs are one of the host determinants for formation/composition of oral microbiota not only for colonization but also for the adaptation to the host niche. Especially, HA enhanced the G. adiacens propagation

Polyunsaturated fatty acids-enriched lipid from reduced sugar alcohol mannitol by marine yeast Rhodosporidiobolus fluvialis Y2

Brown macroalgae is a promising marine biomass for the production of bioethanol and biodiesel fuels. Here we investigate the biochemical processes used by marine oleaginous yeast for assimilating the major carbohydrate found in brown macroalgae. Briefly, yeast Rhodosporidiobolus fluvialis strain Y2 was isolated from seawater and grown in minimal medium containing reduced sugar alcohol mannitol as the sole carbon source with a salinity comparable to seawater. Conditions limiting nitrogen were used to facilitate lipid synthesis. R. fluvialis Y2 yielded 55.1% (w/w) and 39.1% (w/w) of lipids, per dry cell weight, from mannitol in the absence and presence of salinity, respectively. Furthermore, mannitol, as a sugar source, led to an increase in the composition of polyunsaturated fatty acids, linoleic acid (C18:2) and linolenic acid (C18:3), compared to glucose. This suggests that oxidation of mannitol leads to the activation of NADH-dependent fatty acid desaturases in R. fluvialis Y2. Such fatty acid composition may contribute to the cold-flow properties of biodiesel fuels. Our results identified a salt-tolerant oleaginous yeast species with unique metabolic traits, demonstrating a key role as a decomposer in the global carbon cycle through marine ecosystems. This is the first study on mannitol-induced synthesis of lipids enriched with polyunsaturated fatty acids by marine yeast