An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime.

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

Giant Cell Lesions of the Jaws:A Review and Comparative Histopathological Study.

BACKGROUND AND OBJECTIVES: Giant cell lesions (GCLs) are rare lesions which prominently feature multinucleated giant cells in their histology. They include central giant cell granuloma (CGCG), giant cell tumour of bone (GCT), peripheral giant cell granuloma (PGCG), Cherubism (CHB), e.t.c. This study reviewed the clinico-demographic parameters of GCLs of the jaws and assessed the giant cells. METHODS: This was a retrospective study examining the histopathology records of which part of the body of two tertiary institutions. All entries of cases diagnosed as GCLs were retrieved and data were extracted. Also, the giant cells in tissue sections were assessed. Data were analysed using SPSS Inc. version 20 while Chi square test was used to test for association. This was considered significant quand p < 0.05. RESULTS: Over the study period, 2,862 biopsy reports were reviewed. GCLs constituted 48(1.7%) and M: F ratio was 1:1.6 while majority occurred in the 2nd and 3rd decades. The mandible was the most common site recording 27(56.3%) cases and CGCG was the most frequently diagnosed GCL constituting 22(45.8%). Assessment of the giant cells revealed CGCG had predominantly large giant cells, a dense dispersal of giant cells and irregularly shaped giant cells, while CHB mainly had large giant cells with dense dispersal, but round shaped giant cells. CONCLUSION: GCLs are rare lesions commonly seen in females in the 2nd and 3rd decades of life with preference for the mandible. CGCG was the most commonly encountered lesion, while the giant cells in CGCG and CHB were similar in size as well as dispersal.

Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites.

The near-Earth asteroid (162173) Ryugu is a 900-m-diameter dark object expected to contain primordial material from the solar nebula. The Mobile Asteroid Surface Scout (MASCOT) landed on Ryugu's surface on 3 October 2018. We present images from the MASCOT camera (MASCam) taken during the descent and while on the surface. The surface is covered by decimeter- to meter-sized rocks, with no deposits of fine-grained material. Rocks appear either bright, with smooth faces and sharp edges, or dark, with a cauliflower-like, crumbly surface. Close-up images of a rock of the latter type reveal a dark matrix with small, bright, spectrally different inclusions, implying that it did not experience extensive aqueous alteration. The inclusions appear similar to those in carbonaceous chondrite meteorites.

Near-field fluorescence thermometry using highly efficient triple-tapered near-field optical fiber probe.

A novel local temperature measurement method using fluorescence near-field optics thermal nanoscopy (Fluor-NOTN) has been developed. Fluor-NOTN enables nanoscale temperature measurement in situ by detecting the temperature-dependent fluorescence lifetime of CdSe quantum dots (QDs). In this paper, we report a novel triple-tapered near-field optical fiber probe that can increase the temperature measurement sensitivity of Fluor-NOTN. The performance of the proposed probe was numerically evaluated by the finite difference time domain method. Due to improvements in both the throughput and collection efficiency of near-field light, the sensitivity of the proposed probe was 1.9 times greater than that of typical double-tapered probe. The proposed shape of the triple-tapered core was successfully fabricated utilizing a geometrical model. The detected signal intensity of dried layers of QDs was greater by more than two orders than that of auto-fluorescence from the fiber core. In addition, the near-field fluorescence lifetime of the QDs and its temperature dependence were successfully measured by the fabricated triple-tapered near-field optical fiber probe. These measurement results verified the capability of the proposed triple-tapered near-field optical fiber probe to improve the collection efficiency of near-field fluorescence.

Sleeping position, oxygenation and lung function in prematurely born infants studied post term.

OBJECTIVE: To determine the effect of sleeping position on the lung function of prematurely born infants when post term, whether any effect was similar to that before discharge from the neonatal unit, and if it differed according to bronchopulmonary (BPD) status. DESIGN: Prospective study. SETTING: Tertiary neonatal unit. PATIENTS: Twenty infants, median gestational age 30 weeks (range 25-32); 10 had BPD. INTERVENTIONS: Before neonatal unit discharge (median age 36 weeks postmenstrual age (PMA)) and when post term, infants were studied prone and supine, each position maintained for 3 h. MAIN OUTCOME MEASURES: Oxygen saturation was monitored continuously and, at the end of each 3 h period, functional residual capacity (FRC) and compliance (CRS) and resistance (RRS) of the respiratory system were measured. RESULTS: At a median of 36 weeks PMA and 6 weeks later (post term), respectively, oxygen saturation (98% vs 96%, p = 0.001; 98% vs 97%, p = 0.011), FRC (26 vs 24 ml/kg, p<0.0001; 35 vs 31 ml/kg, p = 0.001) and CRS (3.0 vs 2.4 ml/cm H(2)O, p = 0.034; 3.7 vs 2.5 ml/cm H(2)O, p = 0.015) were higher in the prone than the supine position. In the prone position, both BPD and non-BPD infants had significantly greater FRCs on both occasions and oxygen saturation at 36 weeks PMA, but oxygen saturation was significantly better post term only in non-BPD infants. Twelve infants had superior oxygen saturation and 17 superior FRCs in the prone compared with the supine position at both 36 weeks PMA and post term. CONCLUSIONS: These results suggest that lung function impairment does not explain why prematurely born infants are at increased risk of sudden infant death syndrome in the prone compared with the supine position.

Near-field optical mapping of exciton wave functions in a GaAs quantum dot.

Near-field photoluminescence imaging spectroscopy of naturally occurring GaAs quantum dots (QDs) is presented. We successfully mapped out center-of -mass wave functions of an exciton confined in a GaAs QD in real space due to the enhancement of spatial resolution up to 30 nm. As a consequence, we discovered that the spatial profile of the exciton emission, which reflects the shape of a monolayer-high island, differs from that of biexciton emission, due to different distributions of the polarization field for the exciton and biexciton recombinations. This novel technique can be extensively applied to wave function engineering in the design and the fabrication of quantum devices.

Two novel strains of Wolbachia coexisting in both species of mulberry leafhoppers.

Wolbachia is an intracellular symbiont that causes reproductive disorders in many insects. Its presence in the leafhoppers Hishimonoides sellatiformis and Hishimonus sellatus, vectors of mulberry dwarf-Phytoplasma, was confirmed by the PCR analysis of 16S rDNA, ftsZ and wsp. Sequencing of cloned PCR products revealed that two Wolbachia strains coexist in both leafhoppers. The phylogenetic analysis of wsp revealed that these strains belong in novel positions in the B-group of Wolbachia. These strains were detected by PCR and/or PCR-RFLP in all of the tested non-genital organs including salivary glands, as well as in the tested genital organs of Hishimonoides sellatiformis. In addition, Wolbachia-like organisms were observed by electron microscopy in all PCR-positive organs. We discuss the possible horizontal transmission of Wolbachia via mulberry trees.

Kupffer cell-mediated recruitment of rat dendritic cells to the liver: roles of N-acetylgalactosamine-specific sugar receptors.

BACKGROUND & AIMS: Tissue recruitment of dendritic cells (DCs) is essential for antigen presentation. This study aimed to examine cellular and molecular mechanisms for DC recruitment to the liver. METHODS: Purified rat DCs were injected into circulation and their traffics were analyzed in normal and Kupffer cell-depleted rats by intravital confocal microscopy and immunohistology. Affinities of DCs to sinusoidal cells were examined by a cell-binding assay. DC precursor recruitment was induced by particulate injection. RESULTS: Both DC precursors and DCs at the antigen-transporting stage could be recruited to the liver, and their majority initially showed a selective binding to Kupffer cells. In the Kupffer cell-depleted rats, DCs could neither be recruited to the liver nor adhere to sinusoidal walls. Pretreatment with varied monosaccharides showed that sugar residues consisting of N-acetylgalactosamine were necessary for this binding. The binding was calcium-dependent, implying the C-type lectin involvement. Furthermore, DCs could endocytose N-acetylgalactosamine polymers in a receptor-specific manner. CONCLUSIONS: The DC-Kupffer cell binding through N-acetylgalactosamine-specific C-type lectin-like receptors is crucial for DC recruitment to the liver. Rat DCs at least partly possess receptors for endocytosis of galactosylated antigens. These DC receptors as well as Kupffer cell lectins are presumably responsible for this binding.

Trafficking of host- and donor-derived dendritic cells in rat cardiac transplantation: allosensitization in the spleen and hepatic nodes.

BACKGROUND: Kinetics and role of host and donor dendritic cells (DCs) in transplantation immunity are still ill-defined. Using a rat cardiac transplantation model, we studied DC trafficking and sites for allosensitization. METHODS: Host and donor DCs were defined as host- or donor-type class II major histocompatibility complex antigen single-positive cells by double-immunostaining. Proliferative response of both donor and host cells were also analyzed. RESULTS: Host DCs were recruited to the graft soon after transplantation. These cells represented definitive precursors because of high labeling index by a continuous bromodeoxyuridine infusion, their small round shape, and their putative bone marrow origin. Donor interstitial DCs showed a significant self-replicating capability. Both recruited host DCs in a regraft experiment and donor DCs preferentially performed blood-borne migration to the T-cell area of host spleen. Furthermore, they also migrated to the T-cell area of hepatic lymph nodes after executing the sinusoids-lymph translocation as a novel pathway for these DCs. Selectively at their migration sites, a strong T-cell proliferative response occurred, which preceded that in the graft tissues. Removal of spleen and hepatic lymph nodes significantly prolonged the mean graft survival time. CONCLUSION: We conclude that allogeneic heart transplantation induces the recruitment of host DC precursors to the graft tissues and the blood-borne migration of both recruited host and donor DCs to the host spleen and hepatic nodes where effector cells are predominantly sensitized.

In vivo roles of donor and host dendritic cells in allogeneic immune response: cluster formation with host proliferating T cells.

Possible roles of dendritic cells (DCs) in allogeneic immune responses in host lymphoid tissues were characterized in situ by using rat DC transfer and cardiac transplantation models. When allogeneic DCs were intravenously injected, these cells selectively migrated to the T-cell area of hepatic lymph nodes, with peak accumulation at 18 h after injection. Donor DCs and proliferating host T cells formed clusters (rosettes) in which the T-cell proliferative response started. The donor DCs were CD80(+) CD86(+) and, ultrastructurally, were in intimate contact with lymphoblasts within the rosettes. As a novel finding, some of the migrated donor DCs were quickly phagocytosed by putative host interdigitating DCS: By 48 h, the remaining donor DCs had disintegrated within the rosettes. Host interdigitating DCs also formed rosettes throughout the T-cell area, and their kinetics correlated well with that of the T-cell proliferation. In the cardiac allograft model, a few donor DCs selectively migrated to the host spleen and hepatic nodes. Rosette formation by donor and host DCs, phagocytosis of donor DCs, and the T-cell proliferative response occurred in much the same fashion as they did in the first experiment. We conclude that the donor rosettes at the early stage represent the sites of direct allosensitization and those at the late stage represent donor-DC killing. Host rosettes are the sites of T-cell proliferation. In this structure, phagocytosed donor-DC-derived antigens are presumably indirectly presented.

Near-field fluorescence imaging of single molecules with a resolution in the range of 10 nm.

We demonstrate fluorescence imaging of single molecules, by near-field scanning optical microscopy (NSOM), using the illumination-collection mode of operation, with an aperture probe. Fluorescence images of single dye molecules were obtained with a spatial resolution of 15 nm, which is smaller than the diameter of the aperture (20 nm) of the probe employed. Such super-resolution may be attributable to non-radiative energy transfer from the molecules to the coated metal of the probe since the resolution obtained in the case of conventional NSOM is limited to 30-50 nm due to penetration of light into the metal.

Design and optimization of tapered structure of near-field fibre probe based on finite-difference time-domain simulation.

The finite-difference time-domain method was employed to simulate light propagation in tapered near-field fibre probes with small metal aperture. By conducting large-volume simulations, including tapered metal-cladding waveguide and connected optical fibre waveguide, we illustrated the coupling between these guiding modes as well as the electric field distribution in the vicinity of the aperture. The high collection efficiency of a double-tapered probe was reproduced and was ascribed to the shortening of the cut-off region and the efficient coupling to the guiding mode of the optical fibre. The dependence of the efficiency on the tapered structure parameters was also examined.

Near-field spectroscopy of single quantum dots at room temperature.

The observation of photoluminescence spectra of self-assembled single InGaAs quantum dots at room temperature was performed under weak excitation conditions using a near-field scanning optical microscope. Operation in illumination-collection mode with a highly sensitive double-tapered optical fibre probe enabled detection of weak photoluminescence signals at room temperature with high efficiency and high spatial resolution. Each single quantum dot was imaged with a spatial resolution of about 250 nm, which corresponded to a quarter of the wavelength of the photoluminescence from quantum dots. The photoluminescence yields of individual quantum dots were widely distributed and were found to decrease with photoluminescence energy. This result serves as a clue to be pursued for better understanding of the thermal excitation of the carrier from confined states in quantum dots.

Ossiculoplasty using hydroxyapatite prostheses: long-term results.

The surgical results of ossicular chain reconstruction using a hydroxyapatite prosthesis were evaluated in 106 ears of 101 patients who were followed up for > 5 years. Successful reconstruction was defined as: (1) postoperative air-bone gap of

Identification of Mulberry Dwarf Phytoplasmas in the Genital Organs and Eggs of Leafhopper Hishimonoides sellatiformis.

ABSTRACT The presence of mulberry dwarf (MD) phytoplasmas in organs of the inoculative vector insects Hishimonoides sellatiformis and Hishimonus sellatus was determined by means of electron microscopy (EM) and polymerase chain reaction (PCR) assays. Many MD phytoplasmas were detected in genital organs as well as in the intestines, salivary glands, brains, fat bodies, and thoracic ganglia of Hishimonoides sellatiformis, but only in the intestine and salivary glands of Hishimonus sellatus. Many phytoplasmas with characteristic morphology were observed via EM in ovaries, seminal receptacles, and testes, and they were further identified by PCR assays with group I-specific primers. In addition, the organisms were detected by direct or nested PCR assays in eggs (head pigmentation stage of embryos) laid on mulberry shoots by inoculative leafhoppers and in the newly hatched nymphs from these eggs. These findings indicate that transovarial transmission of MD phytoplasmas occurs in Hishimonoides sellatiformis.

Butyrate from bacterial fermentation of germinated barley foodstuff preserves intestinal barrier function in experimental colitis in the rat model.

BACKGROUND AND AIMS: The consumption of germinated barley foodstuff (GBF) prevents inflammation and diarrhoea in a colitis model. In this study we investigated the mechanism of the preventative effect of GBF on experimental colitis in rats, in view of production of bacterial butyrate and preservation of intestinal barrier function. METHODS: Sprague-Dawley rats administered with diets supplemented with 3.5% dextran sodium sulphate were used as an experimental colitis model. Butyrate was given to rats orally or intracaecally. Intestinal barrier function was estimated by light microscopic observation of the mucosa, intestinal permeability and bacterial translocation. RESULTS: Mucosal damage was reduced by intracaecal administration of butyrate, but not by oral administration. Bacterial butyrate production and reduction of mucosal damage depended on the dose of GBF in diets. The action of endogenous bacterial butyrate, including the reduction of intestinal permeability and bacterial translocation, was inhibited by administration of an inhibitor of beta-oxidation of short-chain fatty acids. CONCLUSIONS: The feeding of GBF promotes bacterial butyrate production and improves intestinal barrier function in rats, resulting in mitigation of experimental colitis.

Increased growth of Bifidobacterium and Eubacterium by germinated barley foodstuff, accompanied by enhanced butyrate production in healthy volunteers.

Germinated barley foodstuff (GBF) derived from the aleurone and scutellum fractions of germinated barley mainly consists of low-lignified hemicellulose and glutamine-rich protein. GBF improves the proliferation of intestinal epithelial cells and defecation, through the bacterial production of short chain fatty acids (SCFA), especially butyrate. In this study we investigated the mechanism of production of butyrate by microflora in humans and in vitro. Daily administration of 9 g GBF for 14 successive days significantly increased fecal butyrate content. Fecal Bifidobacterium and Eubacterium were also significantly increased by GBF administration in healthy volunteers. Ten anaerobic micro-organisms selected from intestinal microflora were cultured in vitro in the medium containing GBF as a sole carbon source (GBF medium). After a 3-day incubation, 7 strains (Bifidobacterium breve, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus casei subsp. casei, Bacteroides ovatus, Clostridium butyricum, and Eubacterium limosum) lowered the medium pH producing SCFA. Eubacterium grown together with Bifidobacterium in GBF medium efficiently produced butyrate. On the other hand, GBF changed the intestinal microflora and increased probiotics such as Bifidobacterium in the intestinal tract. As a result, butyrate was produced by the mutual action of Eubacterium and Bifidobacterium. This butyrate is considered to enhance the proliferation of colonic epithelial cells.

Production of D-lyxose from D-glucose by microbial and enzymatic reactions.

D-arabitol was first prepared from D-glucose using Candida famata R28. The reaction gave 5.0% D-arabitol from 10.0% D-glucose. D-arabitol was then almost completely converted to D-xylulose using Acetobacter aceti IFO 3281. Finally, D-lyxose was prepared from D-xylulose enzymatically using L-ribose isomerase from toluene-treated cells of Acinetobacter sp. strain DL-28. The isomerization reaction progressed steadily and the concentration of D-xylulose increased from 1.0 to 10.0%. About 70% of D-xylulose was converted to D-lyxose in all cases. Separation of residual D-xylulose from the reaction mixture is very difficult to achieve by column chromatography, but D-xylulose could be selectively degraded easily using Saccharomyces cerevisiae IFO 0841. The product was crystallized and was confirmed to be D-lyxose by HPLC, 13C-NMR spectra, IR spectra analysis, and optical rotation measurement.

Germinated barley foodstuff increases fecal volume and butyrate production at relatively low doses and relieves constipation in humans.

Germinated barley foodstuff (GBF), derived from the aleurone layer, scutellum and germ of germinated barley, contains a large quantity of fermentable dietary fibers, especially hemicellulose. GBF was given to 9 healthy volunteers in a dose of 9 g of GBF per day for 10 consecutive days, and subsequently 18 g of GBF for another 10 days. As a control, no GBF was given for 3 days before administration of GBF (control period). Fecal weight, water content and short chain fatty acid content were measured before and during the last 3 days of each experimental period. Feeding of GBF significantly increased the fecal butyrate content as well as fecal weight at both dose-levels (9 and 18 g/day), compared with those during the control period. Daily administration of 9 g GBF induced the maximum level of defecation in humans. Relatively mild but chronic constipated volunteers (n = 16) were administered 9 g of GBF daily for 14 days. In this experiment, the condition of defecation (frequency, volume) was estimated by a questionnaire survey. GBF significantly improved defecation within a short period without severe adverse effects. No major abnormalities in laboratory findings were found in hematologic and urinary analyses. In conclusion, daily administration of 9 g GBF was effective for improving defecation in healthy but constipated humans. GBF is a highly safe and effective foodstuff for improving defecation.

Germinated barley foodstuff increases fecal volume and butyrate production in humans.

Germinated barley foodstuff (GBF), derived from the aleurone layer, scutellum and germ of germinated barley, contains a large quantity of fermentable dietary fibers, especially hemicellulose. Ten grams of GBF were given to 10 healthy volunteers 3 times a day (30 g/day/person) for 28 consecutive days. Fecal weight, water contents and short chain fatty acid content were measured before GBF administration and from days 25 to 28 after initiation of GBF administration. GBF intake significantly increased fecal butyrate content as well as fecal weight and water content. No significant change in body weight resulted from consumption of GBF for 28 days. No major laboratory abnormalities were found in hematologic and urinary analysis. These findings indicate that GBF promotes defecation, produces bacterial short chain fatty acids, especially butyrate, without adverse effects, and is a safe foodstuff for humans.