Emission Spectra and Self-Terminating Lasers of Electron-Beam-Produced Rare Gas Plasmas

Plasmas of rare gases (He through Xe) were produced by a short-pulsed, high-current electron beam (600 kV, 10 kA peak, 3 ns FWHM) in a drift tube without an external field over a wide range of pressure (0.l～80 Torr). Emission spectra of the plasmas were observed between 2500 and 8500 Å with a spectrograph and bandpass filters in the directions of end- and side-on views. Short-pulsed laser emissions (3 ns FWHM, 10～400 W peak) traveling along with the electron-beam pulse were found for 20 spectral lines of singly-ionized and neutral Ne, Ar, Kr, and Xe atoms through the end window of the drift tube. The small signal gain coefficients were measured. Temporal behaviors of the emission intensity were observed for the laser lines as well as for many other spontaneous lines through the side window. The atomic processes for the laser excitations have been examined

A Novel Concentrating System of Chicken Stem Cells by Bone Marrow Side Population Cells

Numerous studies in mammalian species have recently been reported that many stem cells have an ability to efficiently efflux the vital DNA-binding dye Hoechst 33342, and it is called side population (SP) cells. However, few study have been reported on the avian SP cells. It could be possible that concentration of hematopoietic stem cells (HSCs) in birds since the characteristic of SIP cells should be shared in various tissues and species. In this study, we first attempted the isolation of SP cells from chicken bone marrow and the assessment by gene expression and morphologic analyses. Bone marrow cells (BMCs) were flushed from the femurs and tibias of chicks aged at 10 days with PBS. The BMCs were layered on lymphocyte separation medium and centrifuged for excluding the erythrocytes. The separated cells were adjusted to 10(6)/ml in HBSS. Hoechst 33342 were added (1.25 mu g/ml) and incubated 60 to 90 minutes at 37 degrees C. Propidium iodide was added (2 mu g/ml) to exclude dead cells. The SP cells were isolated with flow cytometer. The sorted cells were stained with May-Gruenwald Giemsa (MG) for morphological analysis and RNA was extracted for gene expression analysis. The avian SP cells which was vanished by addition verapamil counld be separated. The percentage of SP cells in chicken bone marrow was about 2.6%. The morphological analysis by MG staining indicated that the SP cells had a larger nuclear and little cytoplasm which were typical characterisation of mouse HSCs. The pattern of gene expressions (CD34, c-Kit, CD4 and CD8) in SP cells also resembled that of the mouse HSCs. These results suggested that the HSCs could be enriched from avian bone marrow cells. Together with these results, it was concluded that SP is one of powerful tools for concentration of avian stem cells.ArticleJOURNAL OF POULTRY SCIENCE. 47(1): 53-56(2010)journal articl

Microplasma thruster for ultra-small satellites: Plasma chemical and aerodynamical aspects*

Abstract: A microplasma thruster has been developed of electrothermal type using azimuthally symmetric microwave-excited microplasmas. The microplasma source was ∼2 mm in diameter and ∼10 mm long, being operated at around atmospheric pressures; the micronozzle was a converging-diverging type, having a throat ∼0.2 mm in diameter and ∼1 mm long. Numerical and experimental results with Ar as a working gas demonstrated that this miniature electrothermal thruster gives a thrust of >1 mN, a specific impulse of ~100 s, and a thrust efficiency of ∼10 % at a microwave power of <10 W, making it applicable to attitudecontrol and station-keeping maneuver for a microspacecraft of <10 kg

Acute inflammation at a mandibular solitary horizontal incompletely impacted molar

Acute inflammation is frequently seen in the elderly around incompletely impacted molars located apart from molars or premolars. To identify the factors causing acute inflammation in the solitary molars without second molars or without second and first molars, ages of patients and rates of acute inflammation in 75 horizontal incompletely impacted mandibular molars in contact or not in contact with molars in subjects 41 years old or older were studied using orthopantomographs. Acute inflammation was seen in nine third molars out of 48 third molars in contact with second molars (18.8%), whereas acute inflammation was seen in 11 molars out of 19 solitary molars without second molars or without first and second molars (57.9%) (p < 0.01). The mean age of 48 subjects with third molars in contact with the second molar was 50.42 ± 7.62 years, and the mean age of 19 subjects with isolated molars was 65.16 ± 10.41 years (p < 0.0001). These indicate that a solitary horizontal incompletely impacted molar leads more frequently to acute inflammation along with aging due to possible bone resorption resulting from teeth loss

Five isoforms of the phosphatidylinositol 3-kinase regulatory subunit exhibit different associations with receptor tyrosine kinases and their tyrosine phosphorylations

AbstractThere are five isoforms of the regulatory subunit for the heterodimeric type of phosphatidylinositol 3-kinase. These five regulatory subunit isoforms were overexpressed using an adenovirus transfection system, and their own tyrosine phosphorylations and associations with various tyrosine kinase receptors were investigated. When overexpressed in CHO-PDGFR cells, the associations of these regulatory subunit isoforms with the platelet-derived growth factor receptor were similar. However, when overexpressed in CHO-IR cells, p55γ exhibited a significantly lower ability to bind with IRS-1 upon insulin stimulation, as compared with other regulatory subunit isoforms. Furthermore, p55α and p55γ were found to be tyrosine-phosphorylated. Finally, interestingly, when overexpressed in CHO-EGFR cells or A431 cells and stimulated with epidermal growth factor (EGF), phosphorylated EGF receptor was detected in p85α, p85β and p50α immunoprecipitates, but not in p55α and p55γ immunoprecipitates. In addition, EGF-induced tyrosine phosphorylation was observed in p85α, p85β, p55α and p55γ, but not in p50α, immunoprecipitates. Thus, each regulatory subunit exhibits specific responses regarding both the association with tyrosine-phosphorylated substrates and its own tyrosine phosphorylation. These results suggest that each isoform possesses specific roles in signal transduction, based on its individual tyrosine kinase receptor

Palmitoylation of the canine histamine H2 receptor occurs at Cys305 and is important for cell surface targeting

AbstractTo determine the presence and functional role of the histamine H2 receptor (H2R) palmitoylation, a receptor with a Cys305 to Ala (A305 receptor) mutation was generated. Wild-type (WT) and A305 receptors were tagged at their N-termini with a hemagglutinin (HA) epitope. WT, but not A305, receptors incorporated [3H]palmitate by metabolic labeling, indicating that the H2R is palmitoylated at Cys305. Immunocytochemistry of WT and A305 receptors expressed in COS7 cells revealed WT receptors to be distributed at the plasma membrane, while the majority of A305 receptors were localized intracellularly with only a small portion being at the plasma membrane. However, the affinity of the A305 receptor for tiotidine was comparable to that of the WT receptor. In addition, when the amounts of cell surface receptors as determined by anti-HA antibody binding were equivalent, A305 receptors mediated production of more cAMP than WT receptors. Preincubation of COS7 cells expressing each receptor with 10−5 M histamine for 30 min reduced subsequent cAMP production in response to histamine via the receptors to similar extents, indicating that palmitoylation is not necessary for desensitization. In addition, cell surface A305 receptors were capable of being internalized from the cell surface at a rate and extent similar to those of WT receptors. Finally, CHO cell lines stably expressing either WT or A305 receptors were incubated with 10−5 M histamine for 1, 6, 12 and 24 h. Total amounts of WT and A305 receptors, as determined by tiotidine binding, were reduced by incubation, indicating downregulation. Downregulation of the A305 receptor was more extensive than that of the WT receptor. Thus, palmitoylation of the H2R might be important for targeting to the cell surface and stability

オクタマ ニ オケル シンヨウジュジンコウリン ト コウヨウジュニジリンナイ デノ ノネズミルイコタイグンドウタイ

森林施業に関わる野ネズミ類の役割を明らかにする一環として,林相の異なる針葉樹人工林と広葉樹二次林を跨ぐ形で林内に生息する野ネズミ類を捕獲・放獣する方法により2006年から2009年まで個体群の変動を調査した。その結果,調査対象としたアカネズミ(Apodemus speciosus),ヒメネズミ(Apodemus argenteus)の捕獲個体数は2006年9月には延べワナ数675個で157個体,422回と最高の高密度状態を記録したが,11月から急激な減少が認められ,その後は1年以上ひと月の捕獲個体が数頭という低密度で推移したことから,野ネズミ類個体群にクラッシュが生じたものと判断した。アカネズミとヒメネズミの捕獲個体数の変動を比較すると,それぞれの生息特性を反映して急減の時期に3か月の時間的差異が見られた。しかし,全体的な変動の傾向は両種とも同様の推移を示した。針葉樹林と広葉樹林での生息状況を見ると,アカネズミでは広葉樹林の利用頻度が高く,秋季から冬季にかけて針葉樹林の依存度が増す傾向にあった。ヒメネズミでは針葉樹林のみの利用個体が多いものの,年によっては夏季に広葉樹林のみ利用する個体が増加した。また,いずれの種とも両方の林分を同時に利用している個体は少ないという傾向を得た。行動範囲に関しては,高密度下では大きく,ランダムに分布し,低密度下では小さく,限定的になる傾向が見られた。As a part of clarifying up the role of the forest field mouse, we investigated the fluctuation of the mouse population at an area between a coniferous plantation and a broad-leaved secondary forest in Okutama area, Tokyo. We attempted the capture-recapture method from 2006 to 2009. In September 2006, the captured number of the Apodemus speciosus and A. argenteus surveyed recorded the maximum (157 individuals, 422 caputures in 675 trap night ), but it started decreasing suddenly from November. We judged that a sudden drop occurred in the field mouse population because the captured number of these mice remained low over the next year. Start of the drop in A. argenteus was delayed three months compared to that of A. speciosus. However, both species had a similar population fluctuation tendency. A. speciosus generally used the broad-leaved forest frequently, and they showed increased dependence on the coniferous forest in fall. A. argenteus generally preferred the coniferous forest, but in summer some individuals of both species used only the broad-leaved forest. There were not many individuals whose home ranges extended across both kinds of forests. Home ranges of the field mice tended to be wide and random under a high density situation, but they became narrow and clustered under a low density situation