Dynamics of false vacuum bubbles with nonminimal coupling

We study the dynamics of false vacuum bubbles. A nonminimally coupled scalar field gives rise to the effect of negative tension. The mass of a false vacuum bubble from outside observer's point of view can be positive, zero, or negative. The interior false vacuum has de Sitter geometry, while the exterior true vacuum background can have geometry depending on the vacuum energy. We show that there exist expanding false vacuum bubbles without the initial singularity in the past.Comment: 17 pages, 13 figure

Effect of intradialytic change in blood pressure and ultrafiltration volume on the variation in access flow measured by ultrasound dilution

AbstractBackgroundProspective access flow measurement is the preferred method for vascular access surveillance in hemodialysis (HD) patients. We studied the effect of intradialytic change in blood pressure and ultrafiltration volume on the variation in access flow measured by ultrasound dilution.MethodsAccess flow was measured 30minutes, 120minutes, and 240minutes after the start of HD by ultrasound dilution in 30 patients during 89 HD sessions and evaluated for variation.ResultsThe mean age of the 30 patients was 62±11 years: 19 were male. The accesses comprised 16 fistulae and 14 grafts. The mean access flow over all sessions decreased by 6.1% over time (1265±568mL/min after 30minutes, 1260±599mL/min after 120minutes, and 1197±576mL/min after 240minutes, P<0.01 by repeated measures ANOVA). In addition, a≥5% decrease in mean arterial pressure during HD significantly reduced access flow (P=0.014). However, no other variable (ultrafiltration volume, sex, age, presence of diabetes, type or location of access, body surface area, hemoglobin, serum albumin level) interacted significantly with the effect of time on access flow. Furthermore, mean arterial pressure did not correlate with ultrafiltration volume.ConclusionWe conclude that the variation in access flow during HD is relatively small. Decreased blood pressure is a risk factor for variation in access flow measured by ultrasound dilution. In most patients whose blood pressures are stable during HD, the access flow can be measured at any time during the HD treatment

The Relation between Birth Weight and Insulin Resistance in Korean Adolescents

Low birth weight is associated with insulin resistance and type 2 diabetes in adults. The fetal programming hypothesis has shown that insulin resistance and its associated metabolic disturbances result from a poor gestational environment, for which low birth weight is a surrogate. An at-home questionnaire survey was performed on 660 middle school students (12-15 years) in Seoul, Korea, and 152 cases were randomly selected based on their birth weight. Subjects were divided into three groups according to birth weight. We recorded their birth weight and measured their current anthropometric data, blood pressure, lipid profile, HOMA-IR, and HOMA-β, and compared these parameters among the groups. The relation of birth weight to physiological characteristics in adolescence was examined. Systolic blood pressure, lipid profiles, and fasting plasma glucose, HOMA-β were not significantly different among the groups, but diastolic blood pressure was lower in the third tertile. Insulin, C-peptide, and HOMA-IR were higher in the lower birth weight tertile. After adjustment for confounding factors, birth weight was inversely related to diastolic blood pressure, insulin, C-peptide, and HOMA-IR. We conclude that low birth weight may predict the risk of the insulin resistance and its progression over age, and that adequate gestational nutrition is therefore necessary to prevent low birth weight

The false vacuum bubble nucleation due to a nonminimally coupled scalar field

We study the possibility of forming the false vacuum bubble nucleated within the true vacuum background via the true-to-false vacuum phase transition in curved spacetime. We consider a semiclassical Euclidean bubble in the Einstein theory of gravity with a nonminimally coupled scalar field. In this paper we present the numerical computations as well as the approximate analytical computations. We mention the evolution of the false vacuum bubble after nucleation.Comment: 23 pages, 12 figures, References added, minor correctio

Neurotoxic Manifestations of an Overdose Intrathecal Injection of Gadopentetate Dimeglumine

The intravenous administration of gadopentetate dimeglumine (GD) is relatively safe and rarely causes systemic toxicity in the course of routine imaging studies. However, the general safety of intrathecal GD has not been established. We report a very rare case of an overdose intrathecal GD injection presenting with neurotoxic manifestations, including a decreased level of consciousness, global aphasia, rigidity, and visual disturbance

Cholesterol Granuloma of the Tympanic Membrane Presenting as a Blue Eardrum

Intramembranous tympanic membrane cholesterol granuloma (CG) occurs infrequently. Here, the authors report a case of CG in the tympanic membrane presenting as a blue eardrum in the right ear. In addition, a pinhole perforation noted in the anterosuperior area revealed a brown discharge. High-resolution temporal bone CT showed a bulging mass shadow in the middle ear and a soft tissue dense lesion that filled both the epitympanum and mastoid cavity. Tympanomastoidectomy was performed under general anesthesia. New bone formation was confirmed in the mastoid antrum and epitympanum, and the epitympanum was blocked by new bone. The tympanic membrane revealed a round, brownish mass with a glistening surface and a severely thickened pars tensa. We herein report this case and review pertinent medical literature