180 research outputs found

    Worldsheet Analysis of Gauge/Gravity Dualities

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    Gauge/gravity dualities are investigated from the worldsheet point of view. In [arXiv:0706.1163] and [arXiv:0708.2463], a duality between 4d SYM and supergravity on AdS_5xS^5 has been partly explained by using an anisotropic scale invariance of worldsheet theory. In this paper, we refine the argument and generalize it to lower dimensional cases. We show the correspondence between the Wilson loops in (p+1)-d SYM and the minimal surface in the black p-brane background. Although the scale invariance does not exist in these cases, the generalized scale transformation can be utilized. We also find that the energy density of open strings can be related to the ADM mass of the p-brane without relying on this symmetry.Comment: 19 pages, 8 figure

    Development of a regulatable low-temperature protein expression system using the psychrotrophic bacterium, Shewanella livingstonensis Ac10, as the host

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    A low-temperature protein expression system is useful for the production of thermolabile proteins. We previously developed a system that enables constitutive protein production at low temperatures, using the psychrotrophic bacterium Shewanella livingstonensis Ac10 as the host. To increase the utility of this system, in the present study, we introduced a repressible promoter of the trp operon of this bacterium into the system. When ß-lactamase was produced under the control of this promoter at 18°C and 4°C, the yields were 75 and 33 mg/L-culture, respectively, in the absence of L-Trp, and the yields were decreased by 72% and 77%, respectively, in the presence of L-Trp. We also found that 3-indoleacrylic acid, a competitive inhibitor of the Escherichia coli trp repressor, increased the expression of the reporter gene. This repressible gene expression system would be useful for regulatable recombinant protein production at low temperatures

    Combined Bone Marrow and Kidney Transplantation for the Induction of Specific Tolerance

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    The induction of specific tolerance, in order to avoid the detrimental effects of lifelong systemic immunosuppressive therapy after organ transplantation, has been considered the “Holy Grail” of transplantation. Experimentally, tolerance has been achieved through clonal deletion, through costimulatory blockade, through the induction or infusion of regulatory T-cells, and through the establishment of hematopoietic chimerism following donor bone marrow transplantation. The focus of this review is how tolerance has been achieved following combined bone marrow and kidney transplantation. Preclinical models of combined bone marrow and kidney transplantation have shown that tolerance can be achieved through either transient or sustained hematopoietic chimerism. Combined transplants for patients with multiple myeloma have shown that organ tolerance and prolonged disease remissions can be accomplished with such an approach. Similarly, multiple clinical strategies for achieving tolerance in patients without an underlying malignancy have been described, in the context of either transient or durable mixed chimerism or sustained full donor hematopoiesis. To expand the chimerism approach to deceased donor transplants, a delayed tolerance approach, which will involve organ transplantation with conventional immunosuppression followed months later by bone marrow transplantation, has been successful in a primate model. As combined bone marrow and organ transplantation become safer and increasingly successful, the achievement of specific tolerance may become more widely applicable

    Universal description of viscoelasticity with foliation preserving diffeomorphisms

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    A universal description is proposed for generic viscoelastic systems with a single relaxation time. Foliation preserving diffeomorphisms are introduced as an underlying symmetry which naturally interpolates between the two extreme limits of elasticity and fluidity. The symmetry is found to be powerful enough to determine the dynamics in the first order of strains.Comment: 12 pages, 6 figures, v2:minor changes, v3:clarification adde

    Mobile locally operated detachable end-effector manipulator for endoscopic surgery

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    Purpose\n Local surgery is safer than remote surgery because emergencies can be more easily addressed. Although many locally operated surgical robots and devices have been developed, none can safely grasp organs and provide traction. A new manipulator with a detachable commercial forceps was developed that can act as a third arm for a surgeon situated in a sterile area near the patient. This mechanism can be disassembled into compact parts that enable mobile use.Methods\n A mobile locally operated detachable end-effector manipulator (LODEM) was developed and tested. This device uses crank-slider and cable-rod mechanisms to achieve 5 degrees of freedom and an acting force of more than 5 N. The total mass is less than 15 kg. The positional accuracy and speed of the prototype device were evaluated while performing simulated in vivo surgery.Results\n The accuracy of the mobile LODEM was 0.4 mm, sufficient for handling organs. The manipulator could be assembled and disassembled in 8 min, making it highly mobile. The manipulator could successfully handle the target organs with the required level of dexterity during an in vivo laparoscopic surgical procedure.Conclusions\n A mobile LODEM was designed that allows minimally invasive robotically assisted endoscopic surgery by a surgeon working near the patient. This device is highly promising for robotic surgery applications.ArticleINTERNATIONAL JOURNAL OF COMPUTER ASSISTED RADIOLOGY AND SURGERY. 10(2):161-169 (2015)journal articl

    Reconstruction With Ipsilateral Fibula Transfer With Pasteurized Bone After Excision of Bone Sarcoma of the Tibia

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    We report a technique of implantation of the ipsilateral vascularized fibula with pasteurized recycled bone after excision of tibia sarcoma in two cases. Plate and screws were used for osteosynthesis of the tibia or talus, vascularized fibula, and pasteurized bone. Microsurgery is not necessary for this reconstruction technique. Two patients who underwent this technique have obtained good functional results without tumor relapse 5 and 6 years after operation. The technique produced excellent results with regard to tibial reconstruction in these cases. We found it to be simple, speedy, safe, and a low cost technique by use of recycled bone

    Sample Size Effect of Magnetomechanical Response for Magnetic Elastomers by Using Permanent Magnets

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    The size effect of magnetomechanical response of chemically cross-linked disk shaped magnetic elastomers placed on a permanent magnet has been investigated by unidirectional compression tests. A cylindrical permanent magnet with a size of 35 mm in diameter and 15 mm in height was used to create the magnetic field. The magnetic field strength was approximately 420 mT at the center of the upper surface of the magnet. The diameter of the magnetoelastic polymer disks was varied from 14 mm to 35 mm, whereas the height was kept constant (5 mm) in the undeformed state. We have studied the influence of the disk diameter on the stress-strain behavior of the magnetoelastic in the presence and in the lack of magnetic field. It was found that the smallest magnetic elastomer with 14 mm diameter did not exhibit measurable magnetomechanical response due to magnetic field. On the opposite, the magnetic elastomers with diameters larger than 30 mm contracted in the direction parallel to the mechanical stress and largely elongated in the perpendicular direction. An explanation is put forward to interpret this size-dependent behavior by taking into account the nonuniform field distribution of magnetic field produced by the permanent magnet

    Usefulness of NIRS for medication adherence

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    The symptoms of attention deficit hyperactivity disorder (ADHD) are inattention, hyperactivity, and impulsiveness. Physicians often prescribe methylphenidate (MPH) for children with ADHD for long periods of time. The purpose of the present study was to investigate the usefulness of near-infrared spectroscopy (NIRS) for evaluating drug effects and improvements in medication adherence in children with ADHD. Subjects were 10 male children diagnosed with ADHD : average age, 9.3 years, and 10 boys with typical development : average age 9.5 years. Children with intellectual disability, autism, and obvious depressive symptoms were excluded. The present study revealed that in the ADHD group, oxy-Hb concentrations in the left and right lateral prefrontal cortex significantly increased during the execution of the Stroop color-word test in both channels when taking MPH. This method was considered to be useful for assessing drug effects on ADHD because NIRS is an objective indicator for evaluating ADHD executive dysfunction and visualizes the activation of frontal lobe function by MPH. A pediatric neurologist explained the results of NIRS while presenting images to the ADHD group, and medication adherence and the drug-taking ratio both markedly improved. Therefore, this therapeutic explanation is an effective strategy for improving medication compliance and adherence among patients

    A case of oral cancer with delayed occipital lymph node metastasis: Case report

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    Consideration of unexpected metastasis in patients who have undergone neck dissection with advanced tumors must be anticipated with careful follow-up
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