Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples.

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Compression mechanisms of ferroelectric PbTiO3 via high pressure neutron scattering.

Switchable atomic displacements generate electric dipole moments in ferroelectric materials utilized in many contemporary devices. Lead titanate, a perovskite oxide with formula PbTiO3, has been referred to as a textbook example of a prototype displacive ferroelectric and is a testing platform of widely used models of piezoelectric response of complex solid-solutions. PbTiO3 has been addressed by experimental and computational studies, often with apparently conflicting conclusions. To date, hydrostatic pressure experiments have been interpreted in terms of a model in which the dipole moments gradually diminish with increasing pressure until a transition to a cubic phase, characterized by a zero average dipole moment, occurs. The model unrealistically assumes an even compression of the crystal. Here we show by high-pressure neutron powder diffraction measurements that a fast and slow shrinkage of 12-oxygen cages around Pb and octahedra around Ti, respectively, takes place. A phase diagram consolidating earlier and present results is given.

Juvenile migration of the exclusively pelagic cyprinid, Gnathopogon caerulescens (Honmoroko) in Lake Biwa, Central Japan.

Migration of wild and cultivated juvenile honmoroko Gnathopogon caerulescens of from the spawning and nursery areas in Lake Biwa were investigated, both in the Ibanaiko Lagoon and its outlet to Daido River, using beam-trawl surveys in 2013 and 2014. The study demonstrated migration of G. caerulescens from a nursery lagoon toward Lake Biwa after the juvenile stage. These findings appear to be the first direct evidence for migration of an exclusively pelagic cyprinid species from a littoral nursery to a pelagic adult habitat in a large deep lake.

Expression of inflammation/pain-related genes in the dorsal root ganglion following disc puncture in rats.

PURPOSE: To determine the expression of inflammation- and pain-related genes at days 1 and 3 in the dorsal root ganglion (DRG) of rats with or without disc puncture, using real-time quantitative polymerase chain reaction (RT-qPCR) with the TaqMan low-density array (TLDA). METHODS: 53 female Sprague-Dawley rats were used. The left facet joint between L4 and L5 was removed, and the DRG and intervertebral disc between the vertebrae were exposed. The L4-5 intervertebral disc was punctured using a 0.4-mm diameter injection needle (disc puncture group) or left unpunctured (sham group). After one or 3 days, the 53 DRGs were harvested, frozen, and assessed for expression of inflammation-related genes. Total RNA was isolated from the DRGs. Expression of 119 genes related to inflammation and pain in the DRG after disc puncture were analysed using RT-qPCR with the TLDA. RESULTS: Of the 95 inflammation-related genes, 78 genes were reliably detected. Two genes were significantly up-regulated: cysteinyl leukotriene receptor 1 (CYSLTR1) at day 3 and interleukin 2 receptor gamma (IL2RG) at day 1, and one gene was significantly down-regulated: phospholipase C beta 3 (PLCB3) at day 1. Of the 24 pain-related genes, 18 genes were reliably detected. Two genes were significantly up-regulated: nitric oxide synthase 1 (NOS1) at days 1 and 3 and 5-HT2A receptor (HTR2A) at day 1. CONCLUSION: Disc puncture may elicit changes in the expression of a variety of genes. Gene expression profiling is a useful tool for detecting new potential pharmaceutical targets for spinal pain syndromes.

Response of sex ratio to timing of breeding in the small cyprinid Gnathopogon caerulescens.

The influence of hatching date on the sex ratio of wild Gnathopogon caerulescens was examined. Cohorts reared from eggs collected in the early and middle parts of the spawning season showed almost balanced sex ratios, with female bias in some cohorts. Cohorts born later in the season mostly displayed male bias, and the mean proportion of males later in the season was significantly higher than in early- and mid-season cohorts. These results indicate that the sex ratio of G. caerulescens changes with the time of breeding, increasing along with the ambient water temperature of the lake.

Diel patterns of larval drift of honmoroko Gnathopogon caerulescens in an inlet of Ibanaiko Lagoon, Lake Biwa, Japan.

Diel drift patterns of larvae of the endangered cyprinid Gnathopogon caerelescens in an inlet of the Ibanaiko Lagoon, connected to Lake Biwa in Japan, were assessed in April 2012. Peak occurrence of yolk-sac larvae was within a few hours after dark. Drift of newly hatched larvae is considered to be an important biological mechanism that ensures larval dispersal and recruitment from the inlets (spawning grounds) to the lagoon which functions as a nursery ground.

Phase transitions and thermal-stress-induced structural changes in a ferroelectric Pb(Zr0.80Ti0.20)O3 single crystal.

A single crystal of lead-zirconate-titanate, composition Pb(Zr0.80Ti0.20)O3, was studied by polarized-Raman scattering as a function of temperature. Raman spectra reveal that the local structure deviates from the average structure in both ferroelectric and paraelectric phases. We show that the crystal possesses several, inequivalent complex domain boundaries which show no sign of instability even 200 K above the ferroelectric-to-paraelectric phase transition temperature TC. Two types of boundaries are addressed. The first boundary was formed between ferroelectric domains below TC. This boundary remained stable up to the highest measurement temperatures, and stabilized the domains so that they had the same orientation after repeated heating and cooling cycles. These domains transformed normally to the cubic paraelectric phase. Another type of boundary was formed at 673 K and exhibited no signs of instability up to 923 K. The boundary formation was reversible: it formed and vanished between 573 and 673 K during heating and cooling, respectively. A model in which the crystal is divided into thin slices with different Zr/Ti ratios is proposed. The physical mechanism behind the thermal-stress-induced structural changes is related to the different thermal expansion of the slices, which forces the domain to grow similarly after each heating and cooling cycle. The results are interesting for non-volatile memory development, as it implies that the original ferroelectric state can be restored after the material has been transformed to the paraelectric phase. It also suggests that a low-symmetry structure, stable up to high temperatures, can be prepared through controlled deposition of layers with desired compositions.

Microstrain in tetragonal lead-zirconate-titanate: the effect of pressure on the ionic displacements.

Piezoelectric materials respond to external stimuli by adjusting atomic positions. In solid-solutions, the changes occurring in atomic scale are very complex since the short- and long-range order are different. Standard methods used in diffraction data analysis fail to model the short-range order accurately. Pressure-induced cation displacements in ferroelectric Pb(Zr(0.45)Ti(0.55))O3 perovskite oxide are modeled by starting from a short-range order. We show that the model gives the average structure correctly and properly describes the local structure. The origin of the microstrain in lead zirconate titanate is the spatially varying Zr and Ti concentration and atomic distances, which is taken into account in the simulation. High-pressure neutron powder diffraction and simulation techniques are applied for the determination of atomic positions and bond-valences as a function of pressure. Under hydrostatic pressure, the material loses its piezoelectric properties far before the transition to the cubic phase takes place. The total cation valence +6 is preserved up to 3.31 GPa by compensating the increasing B-cation valence by decreasing Pb-displacement from the high-symmetry position. At 3.31 GPa, Pb-displacement is zero and the material is no more ferroelectric. This is also the pressure at which the Pb-valence is minimized. The average structure is still tetragonal. The model for microstrain predicts that the transition occurs over a finite pressure range: Pb-displacements are spatially varying and follow the distribution of Zr and Ti ions.

Adding diet and exercise counseling to the health promotion plan alleviates anthropometric and metabolic complications in patients with metabolic syndrome.

We investigated the effects of individual (IC) and group (GC) diet and exercise counseling in men with metabolic syndrome. Participants received exercise instruction and exercise load was monitored. IC participants received individual diet counseling sessions and general consultations at baseline and monthly. GC participants received a group diet counseling session at baseline and general consultations at baseline and monthly. In the IC group, body mass index (BMI) percent body fat, waist circumference, diastolic blood pressure, low-density lipoprotein cholesterol, glycosylated hemoglobin A1c, and liver function levels were reduced significantly after 3 months, whereas in the GC group, waist circumference and levels of liver function were reduced. Exercise load was negatively correlated with change in BMI and waist circumference in the IC group, and positively correlated with changes in high-density lipoprotein cholesterol levels in all subjects and in the GC group. Diet and exercise counseling, especially IC, may benefit patients with metabolic syndrome.

Are circulating metabolites important in drug-drug interactions?: Quantitative analysis of risk prediction and inhibitory potency.

The potential of metabolites to contribute to drug-drug interactions (DDIs) is not well defined. The aim of this study was to determine the quantitative role of circulating metabolites in inhibitory DDIs in vivo. The area under the plasma concentration-time curve (AUC) data related to at least one circulating metabolite was available for 71% of the 102 inhibitor drugs identified. Of the 80 metabolites characterized at steady state, 78% had AUCs >10% of that of the parent drug. A comparison of the inhibitor concentration/inhibition constant ([I]/K(i)) ratios of metabolites and the respective parent drugs showed that 17 of the 21 (80%) reversible inhibitors studied had metabolites that were likely to contribute to in vivo DDIs, with some metabolites predicted to have inhibitory effects greater than those of the parent drug. The in vivo drug interaction risks associated with amiodarone, bupropion, and sertraline could be identified from in vitro data only, when data pertaining to metabolites were included in the predictions. In conclusion, cytochrome P450 (CYP) inhibitors often have circulating metabolites that contribute to clinically observed CYP inhibition.

Sarcoidal granulomas in the spleen associated with multiple carcinomas.

Sarcoid reactions are relatively rare manifestations of epithelioid cell granulomas associated with malignancy; they are especially found in the lymph nodes draining malignant tumors, but rarely found in other organs. We present a case of a 60-year-old female with sarcoid reactions in the spleen identified during the consecutive diagnosis and management of ovarian, breast, and thyroid carcinomas during a period of about 2 years. The symptoms and laboratory data suggestive of systemic sarcoidosis were absent except for a slight mediastinal lymphadenopathy detected only by a computed tomographic scan. The splenic granulomas were accompanied by dendritic cells of mature and immature types, the latter being different from the reported nodal counterparts. To our knowledge, this is the first reported case of splenic sarcoid reactions associated with multiple cancers, and the first reported immunohistochemical detection of dendritic cells in splenic granuloma.

The factors behind the morphotropic phase boundary in piezoelectric perovskites.

The best piezoelectric materials are solid solutions in the vicinity of the steep morphotropic phase boundary (MPB) separating rhombohedral and tetragonal phases in the composition-temperature plane. A classical example is the lead zirconate titanate [Pb(Zr(x)Ti(1-x))O(3), PZT] system, with x approximately 0.52, where the two phases are separated by a boundary extending from the lowest temperatures up to several hundred degrees. The origin of the boundary has been under keen studies for 40 years. Recent interest is largely due to the need to develop new, lead-free piezoelectrics, for which a natural starting point is to understand the properties of the present systems. Here, we demonstrate, through high-pressure (up to 8 GPa) neutron powder diffraction experiments and density functional theory computations on lead titanate (PbTiO(3), PT), that it is the competition between two factors which determines the MPB. The first is the oxygen octahedral tilting, giving advantage for the rhombohedral R3c phase, and the second is the entropy, which in the vicinity of the MPB favors the tetragonal phase above 130 K. If the two factors are in balance over a large temperature range, a steep phase boundary results in the pressure-temperature plane.

Search for a light pseudoscalar particle in the decay K_{L};{0}-->pi;{0}pi;{0}X.

We performed a search for a light pseudoscalar particle X in the decay K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma with the E391a detector at KEK. Such a particle with a mass of 214.3 MeV/c;{2} was suggested by the HyperCP experiment. We found no evidence for X and set an upper limit on the product branching ratio for K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma of 2.4x10;{-7} at the 90% confidence level. Upper limits on the branching ratios in the mass region of X from 194.3 to 219.3 MeV/c;{2} are also presented.

Search for the Decay K L0-->pi0nu nu[over].

We performed a search for the K L0-->pi0nu nu[over] decay at the KEK 12-GeV proton synchrotron. No candidate events were observed. An upper limit on the branching ratio for the decay was set to be 6.7 x 10(-8) at the 90% confidence level.

Pressure-induced phase transitions in PbTiO3: a query for the polarization rotation theory.

Our first-principles computations show that the ground state of PbTiO3 under hydrostatic pressure transforms discontinuously from P4mm to R3c at 9 GPa. Spontaneous polarization decreases with increasing pressure so that the R3c phase transforms to the centrosymmetric Rc phase at around 27 GPa. The first-order phase transition between the tetragonal and rhombohedral phases is exceptional since there is no evidence for a bridging phase. The essential feature of the R3c and Rc phases is that they allow the oxygen octahedron to increase its volume VB at the expense of the cuboctahedral volume VA around a Pb ion. This is further supported by the fact that neither the R3m nor Cm phase, which keep the VA/VB ratio constant, is a ground state within the pressure range between 0 and 40 GPa. Thus, tetragonal strain is dominant up to 9 GPa, whereas at higher pressures, efficient compression through oxygen octahedra tilting plays the central role for PbTiO3. Previously predicted pressure induced colossal enhancement of piezoelectricity in PbTiO3 corresponds to unstable Cm and R3m phases. This suggests that the phase instability, in contrast to the polarization rotation, is responsible for the large piezoelectric properties observed in systems like Pb(Zr,Ti)O3 in the vicinity of the morphotropic phase boundary.

Neutron powder diffraction study of Pb(HfxTi1-x)O3 ceramics (0.10

The crystal symmetries of lead hafnate titanate (Pb(HfxTi1-x)O3, PHT) powders with 0.10

Facilitated nitration and oxidation of LDL in cigarette smokers.

BACKGROUND: Cigarette smoking increases the risk of developing atherosclerosis and ischaemic heart disease. Smoking-induced oxidative stress is considered to favour oxidation of low-density lipoprotein (LDL) and subsequently promotes the atherogenic process. We investigated whether peroxynitrite, a reaction product of cigarette smoke, is involved in facilitated oxidation of LDL in smokers. MATERIALS AND METHODS: Plasma LDL was obtained from 10 healthy asymptomatic cigarette smokers and 10 healthy nonsmokers. The state of enhanced oxidative stress in the plasma was assessed by LDL subfraction assay using anion-exchange high-performance liquid chromatography (AE-HPLC) and measurements of thiobarbituric acid-reactive substances (TBARS), 8-hydroxydeoxyguanosine (8-OHdG), vitamin E, 3-nitrotyrosine and 3-chlorotyrosine. RESULTS: Smokers showed a significantly higher level of TBARS and 8-OHdG as well as a significantly lower level of vitamin E than nonsmokers, even after stopping smoking for 10 h or more. The LDL subfraction assay demonstrated an increase in oxidatively modified LDL, as expressed by lower levels of LDL1 and higher levels of LDL2. The 3-nitrotyrosine levels in apolipoprotein B in LDL were significantly higher in smokers than nonsmokers, while the 3-chlorotyrosine levels remained unchanged. In addition, these changes observed in the smokers were further accelerated within 30 min after resumption of cigarette smoking when compared with the levels before smoking resumption. CONCLUSION: The present study suggests that peroxynitrite plays a significant role in oxidative modification of plasma LDL induced by cigarette smoking.

A rat model of dilated cardiomyopathy to investigate partial left ventriculectomy.

BACKGROUND: This study is the first to assess a small animal model of dilated cardiomyopathy (DCM) for evaluation of partial left ventriculectomy. METHOD: Eighteen Dahl salt-sensitive (DS) rats were divided into three groups. Six rats were fed an 8% high-salt diet from the age of 7 weeks (Group 1), and similarly six rats from 8 weeks (Group 2) and six from 9 weeks (Group 3). Blood pressure (BP) was measured by the tail-cuff method and left ventricular (LV) dimensions by echocardiography. RESULTS: In Groups 1 and 2, systolic BP rose and reached 200 mmHg by the 10th to 11th week, when all rats died within a week without signs of heart failure. However, in Group 3, systolic BP gradually rose to 196+/-15 mmHg (mean +/- SD) at the age of 14 weeks, when LV end-diastolic diameter (EDD) was 6.2+/-0.4 mm (control 5.1+/-0.7 mm) and LV fractional shortening (FS) was 77+/-3% (control 68+/-3%). At the age of 25 to 30 weeks, all rats in Group 3 showed signs of congestive heart failure, systolic BP remained high, EDD markedly increased (8.7+/-0.6 mm), and LVFS decreased (38.9+/-8.1%). From this stage, rats survived for 13.7+/-5.9 days. We employed the Group 3 model for our pilot PLV study. Eight rats had PLV with a beating heart by plicating the LV area between the papillary muscle bases. Two rats died perioperatively but the rest survived (60% survival 3 weeks after PLV). Postoperatively, the rats' LVEDD decreased and FS improved significantly. CONCLUSIONS: Using DS rats, we developed a DCM model for investigating PLV. The model may contribute to scientific investigation of PLV.

Effect of molecular charges on renal uptake of 111In-DTPA-conjugated peptides.

The effect of molecular charges on renal accumulation of 111In-DTPA-labeled low molecular weight (LMW) peptides was investigated using 111In-DTPA-octreotide derivatives as models to design radiolabeled peptides that are taken up less by renal cells. The N-terminal D-phenylalanine (Phe) of 111In-DTPA-D-Phe(1)-octreotide was replaced with L-aspartic acid (Asp), L-lysine (Lys), L-methionine (Met) or L-Phe. Cellulose acetate electrophoresis indicated that both 111In-DTPA-L-Phe(1)-octreotide and 111In-DTPA-L-Met(1)-octreotide showed similar net charges, whereas 111In-DTPA-L-alphaLys(1)-octreotide and 111In-DTPA-L-Asp(1)-octreotide had more positive and negative charges, respectively, at pH values similar to those in blood and glomerular filtrate. When injected into mice, significant differences were observed in the renal radioactivity levels. 111In-DTPA-L-alphaLys(1)-octreotide showed the highest radioactivity levels from 10 min to 6 h postinjection, whereas the lowest radioactivity levels were observed with 111In-DTPA-L-Asp(1)-octreotide at all the postinjection intervals. These findings indicated that the replacement of only one amino acid in 111In-DTPA-D-Phe(1)-octreotide significantly altered net molecular charges of the resulting peptides and that the net charges of the 111In-DTPA-octreotide derivatives significantly affected their renal uptake. Thus, an increase of negative charges in peptide molecules may constitute a strategy for designing 111In-DTPA-conjugated LMW peptides with low renal radioactivity levels.