476 research outputs found
Low and high frequency approximations to eigenvibrations of string with double contrasts
We study eigenvibrations for inhomogeneous string consisting of two parts
with strongly contrasting stiffness and mass density. In this work we treat a
critical case for the high frequency approximations, namely the case when the
order of mass density inhomogeneity is the same as the order of stiffness
inhomogeneity, with heavier part being softer. The limit problem for high
frequency approximations depends nonlinearly on the spectral parameter. The
quantization of the spectral semiaxies is applied in order to get a close
approximations of eigenvalues as well as eigenfunctions for the prime problem
under perturbation.Comment: 13 pages, 6 plots; submitted for publication; typos added
Utility of laparoscopic surgery for pelvic abscesses
骨盤内膿瘍に対する治療は,抗生剤による薬物療法が主体であるが,抗生剤無効例や,消化管から発生した膿瘍との鑑別を要する症例では外科的アプローチが必要となる。骨盤内膿瘍の場合,炎症による癒着が強いことが多く,手術は比較的難易度が高い。しかし,高度の炎症で疲弊した患者の負担を軽減するために,近年では腹腔鏡手術が積極的に導入されており,当院でも可能な限り腹腔鏡手術で対応している。抗生剤による治療が無効であった付属器膿瘍に対して腹腔鏡下手術を施行した4症例について報告する。4例とも輸血を要するような出血はなく,また他臓器損傷もなかった。術後は,速やかに炎症所見が改善し特に問題なく経過した。
骨盤内膿瘍に対する腹腔鏡手術は,ドレナージによりすみやかな炎症軽減が可能であり,かつ低侵襲であることから有用性は高い。一方で,(汎発性腹膜炎などで,)腸管麻痺を伴う症例では,腸管の膨隆のため腹腔鏡下の視野確保が困難であり,腹腔鏡手術の適応は慎重であるべきであると考える。Tubo-ovarian abscesses are classically treated with broad-spectrum antibiotics. Frequently, this approach fails, and surgical intervention becomes necessary. In recent years, laparoscopic surgery was positively introduced, and in our hospital, laparoscopic surgery, which is minimally invasive for patients, is selected as much as possible. We performed laparoscopy for four patients with tubo-ovarian abscess that did not improve with antibiotic treatment. No hemorrhage damage to other internal organs was noted in any of the patients. Inflammation was improved immediately, and postoperative progress was good. Usually, surgery for tubo-ovarian abscess is often technically difficult and associated with complications. For peritonitis accompanied with intestinal tract paralysis, it is difficult to secure the field of vision with the laparoscope, and therefore, the indications for laparoscopic surgery should be carefully considered before conducting the surgery
Immunohistochemical Examination for the Distribution of Podoplanin-Expressing Cells in Developing Mouse Molar Tooth Germs
We recently reported the expression of podoplanin in the apical bud of adult mouse incisal tooth. This study was aimed to investigate the distribution of podoplanin-expressing cells in mouse tooth germs at several developing stages. At the bud stage podoplanin was expressed in oral mucous epithelia and in a tooth bud. At the cap stage podoplanin was expressed on inner and outer enamel epithelia but not in mesenchymal cells expressing the neural crest stem cell marker nestin. At the early bell stage nestin and podoplanin were expressed in cervical loop and odontoblasts. At the root formation stage both nestin and podoplanin were weakly expressed in odontoblasts generating radicular dentin. Podoplanin expression was also found in the Hertwig epithelial sheath. These results suggest that epithelial cells of developing tooth germ acquire the ability to express nestin, and that tooth germ epithelial cells maintain the ability to express podoplanin in oral mucous epithelia. The expression of podoplanin in odontoblasts was induced as tooth germ development advanced, but was suppressed with the completion of the primary dentin, suggesting that podoplanin may be involved in the cell growth of odontoblasts. Nestin may function as an intermediate filament that binds podoplanin in odontoblasts
Effects of oxytocin in postmenopausal rats
Recent studies have revealed that the administration of oxytocin has beneficial effects on the regulation of body weight, food intake, and metabolic functions, especially in obese individuals. Obesity is common in women after the menopause and drives many components of metabolic syndrome. Weight gain in menopausal women has been frequently reported. Although obesity and associated metabolic disorders are frequently observed in peri- and postmenopausal women, there are few medical interventions for these conditions. In this study, we evaluated the effects of chronic oxytocin administration on appetite, body weight, and fat mass in peri- and postmenopausal female rats. Sixteen naturally premenopausal or menopausal rats were intraperitoneally injected with oxytocin (1,000 μg/day) for 12 days. The daily changes in their body weight and food intake were measured at the same time as the oxytocin and vehicle injections. Intraperitoneally administering oxytocin for 12 days significantly reduced food intake, body weight, and visceral adipocyte size. In addition, oxytocin administration caused reductions in serum triglyceride and low-density lipoprotein-cholesterol levels, while it did not disturb hepatic or renal functions or locomotor activity. This is the first study to show the effects of oxytocin on the metabolic and feeding functions of peri- and postmenopausal female rats. Oxytocin might be a useful treatment for metabolic disorders caused by the menopause or aging
Spatiotemporal Response of Crystals in X-ray Bragg Diffraction
The spatiotemporal response of crystals in x-ray Bragg diffraction resulting
from excitation by an ultra-short, laterally confined x-ray pulse is studied
theoretically. The theory presents an extension of the analysis in symmetric
reflection geometry [1] to the generic case, which includes Bragg diffraction
both in reflection (Bragg) and transmission (Laue) asymmetric scattering
geometries. The spatiotemporal response is presented as a product of a
crystal-intrinsic plane wave spatiotemporal response function and an envelope
function defined by the crystal-independent transverse profile of the incident
beam and the scattering geometry. The diffracted wavefields exhibit amplitude
modulation perpendicular to the propagation direction due to both angular
dispersion and the dispersion due to Bragg's law. The characteristic measure of
the spatiotemporal response is expressed in terms of a few parameters: the
extinction length, crystal thickness, Bragg angle, asymmetry angle, and the
speed of light. Applications to self-seeding of hard x-ray free electron lasers
are discussed, with particular emphasis on the relative advantages of using
either the Bragg or Laue scattering geometries. Intensity front inclination in
asymmetric diffraction can be used to make snapshots of ultra-fast processes
with femtosecond resolution
Existence and Stability of Standing Pulses in Neural Networks : I Existence
We consider the existence of standing pulse solutions of a neural network
integro-differential equation. These pulses are bistable with the zero state
and may be an analogue for short term memory in the brain. The network consists
of a single-layer of neurons synaptically connected by lateral inhibition. Our
work extends the classic Amari result by considering a non-saturating gain
function. We consider a specific connectivity function where the existence
conditions for single-pulses can be reduced to the solution of an algebraic
system. In addition to the two localized pulse solutions found by Amari, we
find that three or more pulses can coexist. We also show the existence of
nonconvex ``dimpled'' pulses and double pulses. We map out the pulse shapes and
maximum firing rates for different connection weights and gain functions.Comment: 31 pages, 29 figures, submitted to SIAM Journal on Applied Dynamical
System
Effect of Music on Emotions and Respiration
In the present study we investigated whether the emotional state induced by music can change respiratory rate (RR), tidal volume (VT), minute ventilation (VE), and end-tidal CO2concentration (ETCO2). In a pioneering study investigating the effect of music on respiration, the music of Stockhausen and Chopin was used. In the present study, we examined the effects of the same musical stimuli used in that study on respiration. Each stimulus (Stockhausen, Chopin, and silence) was delivered for 30 s and each stimulus was presented five times in random order. Subjects reported feeling uncomfortable listening to Stockhausen\u27s music, but comfortable during Chopin\u27s music and silence. The respiratory response during exposure to Stockhausen\u27s music was rapid and shallow breathing, resulting in an increase in RR. Although the RR was decreased during silence and Chopin\u27s music by Chopin compared with that during Stockhausen\u27s music, there was no significant difference in RR in response to Chopin\u27s music and Stockhausen\u27s music. Although subjects reported feeling comfortable while listening to Chopin\u27s music, the decrease in RR was not significant. The lack of a significant decrease in RR in response to Chopin\u27s music may be due to a mixture of various emotions that may be interconnected to physiological responses, and this higher processing may be peculiar to humans
Study on development policy for new cryogenic structural material for superconducting magnet of fusion reactor
A fusion DEMO will require large-scale cryogenic structure including TF coil cases. Because of huge electromagnetic forces, extra thick plates and/or wrought products will be supplied. Since the midsection of the huge block is weaker than the block surface region, the design yield stress must be determined taking account of this lower strength part. To search the manufacturing process to improve the midsection strength, the crystal refinement strengthening and the precipitation strengthening are considered together with the carbon and nitrogen solid solution strengthening. XM-19 was focused based on the variation of the yield stress and the fracture toughness, a 100 mm thick block and a 30 mm thick plate were trial produced, and strength and the fracture toughness at the midsection were evaluated. This study will present the experimental data and discuss the development policy for a new cryogenic structural material for a fusion reactor
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