607 research outputs found
Products of Floer cohomology of torus fibers in toric Fano manifolds
We compute the ring structure of Floer cohomology groups of Lagrangian torus
fibers in some toric Fano manifolds continuing the study of \cite{CO}. Related
\AI-formulas hold for transversal choice of chains. Two different
computations are provided: a direct calculation using the classification of
holomorphic discs by Oh and the author in \cite{CO}, and another method by
using an {\it analogue of divisor equation} in Gromov-Witten invariants to
thecase of discs.
Floer cohomology rings are shown to be isomorphic to Clifford algebras, whose
quadratic forms are given by the Hessians of functions , which turn out to
be the superpotentials of Landau-Ginzburg mirrors. In the case of \CP^n and
\CP^1 \times \CP^1, this proves the prediction made by Hori, Kapustin and Li
by B-model calculations via physical arguments. The latter method also provides
correspondence between higher derivatives of the superpotential of LG mirror
with the higher products of \AI(or \LI)-algebra of the Lagrangian
submanifold.Comment: 26 pages, 3 fig; Statements about abstract perturbation and
invariance withdrawn. Additional assumption on results about ring structur
Experimental Validation of Fly-Wheel Passive Launch and On-Orbit Vibration Isolation System by Using a Superelastic SMA Mesh Washer Isolator
On-board appendages with mechanical moving parts for satellites produce undesirable micro-jitters during their on-orbit operation. These micro-jitters may seriously affect the image quality from high-resolution observation satellites. A new application form of a passive vibration isolation system was proposed and investigated using a pseudoelastic SMA mesh washer. This system guarantees vibration isolation performance in a launch environment while effectively isolating the micro-disturbances from the on-orbit operation of jitter source. The main feature of the isolator proposed in this study is the use of a ring-type mesh washer as the main axis to support the micro-jitter source. This feature contrasts with conventional applications of the mesh washers where vibration damping is effective only in the thickness direction of the mesh washer. In this study, the basic characteristics of the SMA mesh washer isolator in each axis were measured in static tests. The effectiveness of the design for the new application form of the SMA mesh washer proposed in this study was demonstrated through both launch environment vibration test at qualification level and micro-jitter measurement test which corresponds to on-orbit condition
Effect of an Ethanol Extract of Scutellaria baicalensis on Relaxation in Corpus Cavernosum Smooth Muscle
Aims of study. The aim of the present study was to investigate whether an ethanol extract of Scutellaria baicalensis (ESB) relaxes penile corpus cavernosum muscle in organ bath experiments. Materials and methods. Changes in tension of cavernous smooth muscle strips were determined by penile strip chamber model and in penile perfusion model. Isolated endothelium-intact rabbit corpus cavernosum was precontracted with phenylephrine (PE) and then treated with ESB. Results. ESB relaxed penile smooth muscle in a dose-dependent manner, and this was inhibited by pre-treatment with NG-nitro-l-arginine methyl ester (l-NAME), a nitric oxide (NO) synthase inhibitor, and 1H-[1, 2, 4]-oxadiazolo-[4,3-α]-quinoxalin-1-one (ODQ), a soluble guanylyl cyclase (sGC) inhibitor. ESB-induced relaxation was significantly attenuated by pretreatment with tetraethylammonium (TEA), a nonselective K+ channel blocker, and charybdotoxin, a selective Ca2+-dependent K+ channel inhibitor. ESB increased the cGMP levels of rabbit corpus cavernosum in a concentration-dependent manner without changes in cAMP levels. In a perfusion model of penile tissue, ESB also relaxed penile corpus cavernosum smooth muscle in a dose-dependent manner. Conclusion. Taken together, these results suggest that ESB relaxed rabbit cavernous smooth muscle via the NO/cGMP system and Ca2+-sensitive K+ channels in the corpus cavernosum
Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial.
Background:For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. Methods:We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48) or a control group (n = 22). We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. Results:The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0%) patients achieved the primary goal, as compared with 16 (72.7%) in the control group (P = 0.430). The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087), but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851). However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193). The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363) nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569). Conclusion:Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy
Degradation of Serotonin N-Acetyltransferase, a Circadian Regulator, by the N-end Rule Pathway
Serotonin N-acetyltransferase (AANAT) converts serotonin to N-acetylserotonin (NAS), a distinct biological regulator and the immediate precursor of melatonin, a circulating hormone that influences circadian processes, including sleep. N-terminal sequences of AANAT enzymes vary among vertebrates. Mechanisms that regulate the levels of AANAT are incompletely understood. Previous findings were consistent with the possibility that AANAT may be controlled through its degradation by the N-end rule pathway. By expressing the rat and human AANATs and their mutants not only in mammalian cells but also in the yeast Saccharomyces cerevisiae, and by taking advantage of yeast genetics, we show here that two complementary forms of rat AANAT are targeted for degradation by two complementary branches of the N-end rule pathway. Specifically, the Nα terminally acetylated (Nt-acetylated) Ac-AANAT is destroyed through the recognition of its Nt acetylated N terminal Met residue by the Ac/N-end rule pathway, whereas the non Nt acetylated AANAT is targeted by the Arg/N end rule pathway, which recognizes the unacetylated N-terminal Met-Leu sequence of rat AANAT. We also show, by constructing lysine to arginine mutants of rat AANAT, that its degradation is mediated by polyubiquitylation of its Lys residue(s). Human AANAT, whose N-terminal sequence differs from that of rodent AANATs, is longer lived than its rat counterpart, and appears to be refractory to degradation by the N-end rule pathway. Together, these and related results indicate both a major involvement of the N-end rule pathway in the control of rodent AANATs and substantial differences in the regulation of rodent and human AANATs that stem from differences in their N terminal sequences
Stemness Evaluation of Mesenchymal Stem Cells from Placentas According to Developmental Stage: Comparison to Those from Adult Bone Marrow
This study was done to evaluate the stemness of human mesenchymal stem cells (hMSCs) derived from placenta according to the development stage and to compare the results to those from adult bone marrow (BM). Based on the source of hMSCs, three groups were defined: group I included term placentas, group II included first-trimester placentas, and group III included adult BM samples. The stemness was evaluated by the proliferation capacity, immunophenotypic expression, mesoderm differentiation, expression of pluripotency markers including telomerase activity. The cumulative population doubling, indicating the proliferation capacity, was significantly higher in group II (P<0.001, 31.7±5.8 vs. 15.7±6.2 with group I, 9.2±4.9 with group III). The pattern of immunophenotypic expression and mesoderm differentiation into adipocytes and osteocytes were similar in all three groups. The expression of pluripotency markers including ALP, SSEA-4, TRA-1-60, TRA-1-81, Oct-4, and telomerase were strongly positive in group II, but very faint positive in the other groups. In conclusions, hMSCs from placentas have different characteristics according to their developmental stage and express mesenchymal stemness potentials similar to those from adult human BMs
bending resistance and cyclic fatigue resistance of waveone gold reciproc blue and hyflex edm instruments
Abstract Background/purpose Several single-file systems manufactured using different heat treatment and operated by different kinematics have been released. This study compared the bending resistance and cyclic fatigue resistance of three NiTi files, and examined their phase-transformation behavior. Materials and methods WaveOne Gold Primary (WOG), Reciproc Blue R25 (RPB), and HyFlex EDM OneFile (HDM) were tested (N = 40/instrument). A vertical load was applied to a point 3 mm from the tip, and the stress was measured until a displacement of 3 mm. Tests were conducted at either room temperature (RT: 22 °C) or body temperature (BT: 37 °C) (n = 10). Cyclic fatigue resistance tests were performed in an artificial canal, which had a curvature angle of 40° and a 5-mm radius. Tests were conducted at either RT or BT (n = 10). Instruments were operated according to the manufacturers' instructions. Test results were analyzed using the Kruskal–Wallis and the Mann–Whitney tests. Additional three instruments of each brand were subjected to differential scanning calorimetry (DSC). Results At RT the bending resistance of three files were not significantly different. However, at BT the bending resistance of RPB was highest, followed by WOG, and HDM (P Conclusion HDM presented superior flexibility and cyclic fatigue resistance at BT
THE INCIDENCE, CLINICAL PREDICTORS AND PROGNOSTIC VALUE OF REVERSE LEFT VENTRICULAR REMODELING IN PATIENTS WITH STEMI UNDERGOING PRIMARY PCI
- …