425 research outputs found
Relaxation Theory for Point Vortices
We study relaxation dynamics of the mean field of many point vortices from quasi-equilibrium to equilibrium. Maximum entropy production principle implies four consistent equations concerning relaxation-equilibrium states and patch-point vortex models. Point vortex relaxation equation coincides with Brownian point vortex equation in micro-canonical setting. Mathematical analysis to point vortex relaxation equation is done in accordance with the Smoluchowski-Poisson equation
Fixed points of log-linear discrete dynamics
In this paper we study the fixed points of the Log-linear discrete dynamics. We show that almost all Log-linear dynamics have at most two fixed points which is a generalization of Soni's result
Relaxation Dynamics of Point Vortices
We study a model describing relaxation dynamics of point vortices, from quasi-stationary state to the stationary state. It takes the form of a mean field equation of Brownian point vortices derived from Chavanis, and is formulated by our previous work as a limit equation of the patch model studied by Robert-Someria. This model is subject to the micro-canonical statistic laws; conservation of energy, that of mass, and increasing of the entropy. We study the existence and nonexistence of the global-in-time solution. It is known that this profile is controlled by a bound of the negative inverse temperature. Here we prove a rigorous result for radially symmetric case. Hence E/M2 large and small imply the global-in-time and blowup in finite time of the solution, respectively. Where E and M denote the total energy and the total mass, respectively
Integrin Inhibitors as a Therapeutic Agent for Ovarian Cancer
Ovarian cancer is a deadly disease, with a cure rate of only 30%. Despite aggressive treatments, relapse remains almost inevitable in patients with advanced-stage disease. In recent years, great progress has been made towards targeting integrins in cancer treatment, and clinical studies with various integrin inhibitors have demonstrated their effectiveness in blocking cancer progression. Given that the initial critical step of ovarian cancer metastasis is the attachment of cancer cells onto the peritoneum or omentum, in addition to the proven positive clinical results of anti-angiogenic therapy, targeting integrins is likely to be one of the most feasible approaches. This paper summarizes the current understanding of the integrin biology in ovarian cancer metastasis and the various therapeutic approaches attempted with integrin inhibitors. Although no integrin inhibitors have shown favorable results so far, integrin-targeted therapies continue to be a promising approach to be explored for further clinical investigation
Dermoscopic Features of a Black Hairy Tongue in 2 Japanese Patients
Dermoscopic features of a black hairy tongue have never been reported. Dermoscopy might be useful in speculating pathologic features of oral lesions. The objective was to identify additional dermoscopic criteria. Two Japanese patients who were clinically given a diagnosis of “black hairy tongue” were evaluated for dermoscopic features. We have shown characteristic dermoscopic features of brownish hair-like elongation of filiform papillae with whitish lingual papillae. Dermoscopic examination seemed useful as an adjunct to the diagnosis of this benign disorder of the tongue, demonstrating exact changes in shape and color of filiform papillae. It might also be helpful in more objective observation of the therapeutic efficacy
Rhabdomyolysis with Multiple Electrolyte Imbalances under Proton Pump Inhibitor Treatment after Total Thyroidectomy
A 90-year-old man presented with muscle weakness, difficulty concentrating, and dysphagia. About eighteen months prior to presentation, lansoprazole had been initiated to prevent stress ulcers; he also had a history of total thyroidectomy due to papillary thyroid cancer ten years prior. Laboratory findings were as follows: K 2.4 mEq/L, Ca 3.7 mg/dL, Mg 1.3 mg/dL, CK 5386 U/L, and intact PTH (iPTH) 14 pg/mL. Rhabdomyolysis with multiple electrolyte imbalances under proton pump inhibitor (PPI) treatment was diagnosed. We initiated intravenous hydration and electrolyte supplementation with discontinuation of PPI. After discontinuing PPI, the patient’s serum magnesium, potassium, and calcium levels normalised with oral vitamin D and calcium supplementation. PPIs can cause hypocalcaemia and hypokalaemia via hypomagnesemia; hypocalcaemia is also a common postoperative complication of thyroidectomy. Careful monitoring of electrolyte levels is required in patients with long-term PPI treatment, especially in post-thyroidectomy cases
Potent Inhibitory Effects of D-tagatose on the Acid Production and Water-insoluble Glucan Synthesis of Streptococcus mutans GS5 in the Presence of Sucrose
We examined and compared the inhibitory effects of D-tagatose on the growth, acid production, and water-insoluble glucan synthesis of GS5, a bacterial strain of Streptococcus mutans, with those of xylitol, D-psicose, L-psicose and L-tagatose. GS5 was cultured for 12h in a medium containing 10オ (w/v) of xylitol, D-psicose, L-psicose, D-tagatose or L-tagatose, and the inhibitory effect of GS5 growth was assessed. Each sugar showed different inhibitory effects on GS5. Both D-tagatose and xylitol significantly inhibited the acid production and water-insoluble glucan synthesis of GS5 in the presence of 1オ (w/v) sucrose. However, the inhibitory effect of acid production by D-tagatose was significantly stronger than that of xylitol in presence of sucrose
Dermoscopic Features of Pigmented Bowen's Disease in a Japanese Female Mimicking Malignant Melanoma
Various structures have been reported for dermoscopic features of pigmented Bowen's disease (BD), which could be a mimic of various pigmented skin lesions. A 79-year-old Japanese woman presented with a 3-year history of brown-black macule on her right upper arm without symptom. Dermoscopic examination demonstrated irregular flossy streaks, irregular brown dots/globules, blue-whitish regression structures, and overlaying whitish scaly areas. We suspected pigmented skin lesions including seborrheic keratosis, pigmented eccrine poroma, and malignant melanoma and excised completely with a 5 mm margin. Histopathological features were consistent with a diagnosis of pigmented BD. Although similar dermoscopic features might be revealed in pigmented skin lesions and it may occasionally be difficult to distinguish between pigmented BD and other pigmented skin lesions, dermoscopy would be useful in speculating pathologic features of pigmented BD
Cold-induced metabolic conversion of haptophyte di- to tri-unsaturated C37 alkenones used as palaeothermometer molecules
The cosmopolitan marine haptophyte alga Emiliania huxleyi accumulates very long-chain (C37-C40) alkyl ketones with two to four trans-type carbon-carbon double bonds (alkenones). These compounds are used as biomarkers of haptophytes and as palaeothermometers for estimating sea-surface temperatures in biogeochemistry. However, the biosynthetic pathway of alkenones in algal cells remains enigmatic, although it is well known that the C37 tri-unsaturated alkenone (K37:3) becomes dominant at low temperatures, either by desaturation of K37:2 or by a separate pathway involving the elongation of tri-unsaturated alkenone precursors. Here, we present experimental evidence regarding K37:3 synthesis. Using the well-known cosmopolitan alkenone producer E. huxleyi, we labelled K37:2 with 13C by incubating cells with 13C-bicarbonate in the light at 25 °C under conditions of little if any K37:3 production. After stabilisation of the 13C-K37:2 level by depleting 13C-bicarbonate from the medium, the temperature was suddenly reduced to 15 °C. The 13C-K37:2 level rapidly decreased, and the 13C-K37:3 level increased, whereas the total 13C-K37 level—namely [K37:2 + K37:3]—remained constant. These 13C-pulse-chase-like experimental results indicate that 13C-K37:2 is converted directly to 13C-K37:3 by a desaturation reaction that is promoted by a cold signal. This clear-cut experimental evidence is indicative of the existence of a cold-signal-triggered desaturation reaction in alkenone biosynthesis
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