130 research outputs found
Universal turbulence on branes in holography
At a meson melting transition in holographic QCD, a weak turbulence of mesons
was found with critical embeddings of probe D-branes in gravity duals. The
turbulent mesons have a power-law energy distribution where is the mass of the -th excited resonance
of the meson tower. In this paper, we find that the turbulence power
is universal, irrespective of how the transition is driven, by numerically
calculating the power in various static brane setups at criticality. We also
find that the power depends only on the cone dimensions of the probe
D-branes.Comment: 28 pages, 16 figures, v2: a reference adde
Flying Instability due to Organic Compounds in Hard Disk Drive
The influence of organic compounds (OCs) on the head-disk interface (HDI) was investigated in hard disk drives. The drives were tested at high temperature to investigate the influence of gaseous OC and to confirm if the gaseous OC forms droplets on head or disk. In the experiment, errors occurred by readback signal jump and we observed the droplets on the disk after full stroke seek operation of the drive. Our results indicate that the gaseous OC condensed on the slider and caused flying instability resulting in drive failure due to slider contact with a droplet of liquid OC. Furthermore, this study shows that kinetic viscosity of OC is an important factor to cause drive failure using alkane reagents
Magnetic instability in AdS/CFT : Schwinger effect and Euler-Heisenberg Lagrangian of Supersymmetric QCD
To reveal the Schwinger effect for quarks, i.e., pair creation process of
quarks and antiquarks, we derive the vacuum decay rate at strong coupling using
AdS/CFT correspondence. Magnetic fields, in addition to the electric field
responsible for the pair creation, causes prominent effects on the rate, and is
important also in experiments such as RHIC/LHC heavy ion collisions. In this
paper, through the gravity dual we obtain the full Euler-Heisenberg Lagrangian
of N=2 supersymmetric QCD and study the Schwinger mechanism with not only a
constant electric field but also a constant magnetic field as external fields.
We determine the quark mass and temperature dependence of the Lagrangian. In
sharp contrast with the zero magnetic field case, we find that the imaginary
part, and thus the vacuum decay rate, diverges in the massless zero-temperature
limit. This may be related to a strong instability of the QCD vacuum in strong
magnetic fields. The real part of the Lagrangian serves as a generating
function for non-linear electro-magnetic responses, and is found such that the
Cotton-Mouton effect vanishes. Interestingly, our results of the Schwinger /
Cotton-Mouton effects coincide precisely with those of N=2 supersymmetric QED.Comment: 21 pages. v2:references added, footnotes adde
Electromagnetic instability in holographic QCD
Using the AdS/CFT correspondence, we calculate the vacuum decay rate for the
Schwinger effect in confining large gauge theories. The instability is
induced by the quark antiquark pair creation triggered by strong
electromagnetic fields. The decay rate is obtained as the imaginary part of the
Euler-Heisenberg effective Lagrangian evaluated from the D-brane action with a
constant electromagnetic field in holographic QCD models such as the
Sakai-Sugimoto model and the deformed Sakai-Sugimoto model. The decay rate is
found to increase with the magnetic field parallel to the electric field, while
it decreases with the magnetic field perpendicular to the electric field. We
discuss generic features of a critical electric field as a function of the
magnetic field and the QCD string tension in the Sakai-Sugimoto model.Comment: 19 pages, v2: a reference adde
Delayed Tooth Replantation after Root Surface Treatment with Papain and Sodium Fluoride in Rats: A Histological and Histomorphometrical Evaluation
Introduction: The aim of this study was to examine the histological effect of papain and sodium fluoride in delayed replantation of rat incisor teeth on the repair process. Methods and Materials: Forty upper incisors of Wistar rats were randomly assigned to four groups (n=10). In group I, the dental papilla and the pulp tissue of extracted teeth were removed before immediate replantation in their sockets. In the other groups, the extracted teeth were maintained in dry storage for 60 min and subjected to different root surface treatments. In group II, the teeth were immersed in 10% papain for 20 min, scrubbed with gauze soaked in saline for 1 min, and immersed in a 2% acidulated-phosphate sodium fluoride solution for 20 min. In group III, the teeth were immersed in saline for 20 min, scrubbed with gauze soaked in saline for 1 min, and immersed in a 2% acidulated-phosphate sodium fluoride solution for 20 min. In group IV, root surface treatment was not applied. The root canals were treated and filled with a calcium hydroxide paste and the teeth were replanted. The animals were euthanized after 60 days and anatomic specimens containing the teeth were subjected to routine histochemical processing and staining with hematoxylin and eosin. The Kruskal-Wallis test was used, followed by the Dunn’s test for multiple comparisons. Results: Groups I and II had less inflammatory root resorption and total area of root resorption (P<0.05) than groups III and IV respectively. Conclusions: Based on this animal study, root surface treatment with papain and sodium fluoride in delayed tooth replantation showed greater efficacy in controlling inflammatory root resorption and may be a viable option for clinical application
Formation of naphthodithiophene isomers by flash vacuum pyrolysis of 1,6-di(2-thienyl)- and 1,6-di(3-thienyl)-1,5-hexadien-3-ynes
The paleoenvironmental change recorded in core sediments of Lake Abashiri of subarctic zone in the east part of Hokkaido, Japan
第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月27日(火) 国立極地研究所 3階ラウン
Negatively charged low-density lipoprotein is associated with atherogenic risk in hypertensive patients
Negatively charged low-density lipoprotein (LDL), generated via multiple processes such as oxidation, acetylation, or glycosylation, plays a key role in the initiation and progression of atherosclerosis and related diseases. Anion-exchange high-performance liquid chromatography (AE-HPLC) can subfractionate LDL into LDL-1, LDL-2, and LDL-3 based on LDL particle charge, but the clinical significance of LDL subfractions has not yet been elucidated. The aim of this study was to determine the clinical significance of these fractions with particular regard to atherogenic risk in hypertensive patients. Ninety-eight patients with essential hypertension (age 67.0 ± 10.7 years; 54 males) were enrolled in the present study. The relationships between LDL subfractions and atherogenic risk factors, including lipid profiles, blood pressure and plasma 8-isoprostane as a marker of oxidative stress, were examined. LDL-1 levels were significantly and negatively correlated with body mass index (r = -0.384, p < 0.001), systolic blood pressure (r = -0.457, p < 0.001), non-high-density lipoprotein cholesterol levels (r = -0.457, p < 0.001) and 8-isoprostane levels (r = -0.415, p < 0.001). LDL-3, which is the most negatively charged fraction of total LDL, was significantly and positively correlated with these parameters (r = 0.267, 0.481, 0.357, and 0.337, respectively). LDL-1 levels were significantly lower (p < 0.001), and LDL-2 and LDL-3 levels were significantly higher (each p < 0.001) in patients with poorly controlled hypertension than in patients with well-controlled hypertension. In addition, an increase in the total number of traditional risk factors at time of study participation, but not previous diagnosis, was associated with a decrease in LDL-1 levels and increases in LDL-2 and LDL-3 levels. These data suggest that LDL subfractions are associated with multiple atherogenic risk factors and that treatment to modify these risk factors could result in Negatively charged low-density lipoprotein (LDL), generated via multiple processes such as oxidation, acetylation, or glycosylation, plays a key role in the initiation and progression of atherosclerosis and related diseases. Anion-exchange high-performance liquid chromatography (AE-HPLC) can subfractionate LDL into LDL-1, LDL-2, and LDL-3 based on LDL particle charge, but the clinical significance of LDL subfractions has not yet been elucidated. The aim of this study was to determine the clinical significance of these fractions with particular regard to atherogenic risk in hypertensive patients. Ninety-eight patients with essential hypertension (age 67.0 ± 10.7 years; 54 males) were enrolled in the present study. The relationships between LDL subfractions and atherogenic risk factors, including lipid profiles, blood pressure and plasma 8-isoprostane as a marker of oxidative stress, were examined. LDL-1 levels were significantly and negatively correlated with body mass index (r = −0.384, p < 0.001), systolic blood pressure (r = −0.457, p < 0.001), non-high-density lipoprotein cholesterol levels (r = −0.457, p < 0.001) and 8-isoprostane levels (r = −0.415, p < 0.001). LDL-3, which is the most negatively charged fraction of total LDL, was significantly and positively correlated with these parameters (r = 0.267, 0.481, 0.357, and 0.337, respectively). LDL-1 levels were significantly lower (p < 0.001), and LDL-2 and LDL-3 levels were significantly higher (each p < 0.001) in patients with poorly controlled hypertension than in patients with well-controlled hypertension. In addition, an increase in the total number of traditional risk factors at time of study participation, but not previous diagnosis, was associated with a decrease in LDL-1 levels and increases in LDL-2 and LDL-3 levels. These data suggest that LDL subfractions are associated with multiple atherogenic risk factors and that treatment to modify these risk factors could result in changes in LDL subfraction levels. In conclusion, LDL subfractions isolated by AE-HPLC may represent a marker of atherogenic risk in patients with hypertension
Essential anatomy for lateral lymph node dissection
In Western countries, the gold-standard therapeutic strategy for rectal cancer is preoperative chemoradiotherapy (CRT) following total mesorectal excision (TME), without lateral lymph node dissection (LLND). However, preoperative CRT has recently been reported to be insufficient to control lateral lymph node recurrence in cases of enlarged lateral lymph nodes before CRT, and LLND is considered necessary in such cases. We performed a literature review on aspects of pelvic anatomy associated with rectal surgery and LLND, and then combined this information with our experience and knowledge of pelvic anatomy. In this review, drawing upon research using a 3-dimensional anatomical model and actual operative views, we aimed to clarify the essential anatomy for LLND. The LLND procedure was developed in Asian countries and can now be safely performed in terms of functional preservation. Nonetheless, the longer operative time, hemorrhage, and higher complication rates with TME accompanied by LLND than with TME alone indicate that LLND is still a challenging procedure. Laparoscopic or robotic LLND has been shown to be useful and is widely performed; however, without a sufficient understanding of anatomical landmarks, misrecognition of vessels and nerves often occurs. To perform safe and accurate LLND, understanding the landmarks of LLND is essential
CD146 is a potential immunotarget for neuroblastoma
Neuroblastoma, the most common extracranial solid tumor of childhood, is thought to arise from neural crest-derived immature cells. The prognosis of patients with high-risk or recurrent/refractory neuroblastoma remains quite poor despite intensive multimodality therapy; therefore, novel therapeutic interventions are required. We examined the expression of a cell adhesion molecule CD146 (melanoma cell adhesion molecule [MCAM]) by neuroblastoma cell lines and in clinical samples and investigated the anti-tumor effects of CD146-targeting treatment for neuroblastoma cells both in vitro and in vivo. CD146 is expressed by 4 cell lines and by most of primary tumors at any stage. Short hairpin RNA-mediated knockdown of CD146, or treatment with an anti-CD146 polyclonal antibody, effectively inhibited growth of neuroblastoma cells both in vitro and in vivo, principally due to increased apoptosis via the focal adhesion kinase and/or nuclear factor-kappa B signaling pathway. Furthermore, the anti-CD146 polyclonal antibody markedly inhibited tumor growth in immunodeficient mice inoculated with primary neuroblastoma cells. In conclusion, CD146 represents a promising therapeutic target for neuroblastoma
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