• Journal of the Microelectronics and Packaging Society
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• v.6 no.2
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• pp.69-74
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• 1999

Graphite and carbonaceous materials intercalate and deintercalate Li-ion reversibly into their layered structures. These materials show an excellent capacity for using a negative electrode in Li-ion batteries, because the electrochemical potential of Li-ion intercalated carbon is almost identical with that of lithium metal. Carbon used in this study was obtained by the pyrolysis of petroleum pitch, and heat-treated at the several temperatures between $700^{\circ}C$ and $1300^{\circ}C$. XRD analysis revealed that crystallization of carbon increased with increasing the heat treatment temperature. Charge/discharge properties were studied by a constant-current step at the rate of 0.1C, and the interfacial reaction between the electrolyte and the surface of carbon electrode was studied by cyclic voltammetry. Cell capacities were investigated in terms of the heat treatment temperature and the cycle number. Reversible capacity increased with the heat treatment temperature up to $1000^{\circ}C$, thereafter decreased continuously. Also, charge capacity decreased with the cycle number, while the reversibility improved with it.

• Journal of Embryo Transfer
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• v.18 no.3
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• pp.263-267
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• 2003

This study was carried out to test the efficacy of pharmacological inhibitors of the cell cycle transition in keeping bovine oocytes at the germinal vesicle(GV) stage and the reversibility of this inhibition. Bovine oocytes were incubated for 22∼24 hrs in the presence of various inhibitors : cycloheximide (2$\mu\textrm{g}$/$m\ell$), 6-DMAP (2 mM), and roscovitine (50$\mu$M). Bovine oocytes cultured with any of the inhibitors were significantly blocked at the GV stage. Reversibility of pharmacological inhibitors was assessed by culturing oocytes an additional 22∼24 hours in inhibitor-free medium. Examination of oocytes revealed that the inhibitory effect was fully reversible and effect of resuming meiotic progression on nuclear maturation varied according to the various inhibitors. This study suggests that cycloheximide, 6-DMAP and roscovitine can be applied to control meiotic arrest and resumption in maturation culture of bovine oocytes in vitro. More investigations are needed to better understand how the cell cycle of oocyte is blocked without problems to future developmental competence.

• Structural Engineering and Mechanics
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• v.82 no.1
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• pp.107-120
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• 2022

The bracing members capable of active control against seismic loads to reduce earthquake damage have been widely utilized in construction projects. Effectively reducing the structural damage caused by earthquake events, bracing systems equipped with retrofitting damper devices, which take advantage of the energy dissipation and impact absorption, have been widely used in practical construction sites. Shape Memory Alloys (SMAs) are a new generation of smart materials with the capability of recovering their predefined shape after experiencing a large strain. This is mainly due to the shape memory effects and the superelasticity of SMA. These properties make SMA an excellent alternative to be used in passive, semi-active, and active control systems in civil engineering applications. In this research, a new system in diagonal braces with slit damper combined with SMA is investigated. The diagonal element under the effect of tensile and compressive force turns to shear force in the slit damper and creates tension in the SMA. Therefore, by creating shear forces in the damper, it leads to yield and increases the energy absorption capacity of the system. The purpose of using SMA, in addition to increasing the stiffness and strength of the system, is to create reversibility for the system. According to the results, the highest capacity is related to the case where the ratio of the width of the middle section to the width of the end section (b₁/b) is 1.0 and the ratio of the height of the middle part to the total height of the damper (h₁/h) is 0.1. This is mainly because in this case, the damper section has the highest cross-section. In contrast, the lowest capacity is related to the case where b₁/b=0.1 and the ratio h₁/h=0.8.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.1-7
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• 2013

Purpose : The purpose of this study is to correlate the imaging findings and the clinical findings in patients with transient splenial lesions (TSL). Materials and Methods: Total of 7 patients (M: F = 4: 3; age range 11 - 38 years, mean age 25.5 years) were studied between November 2006 and April 2011. The MRI findings and clinical findings in all patients were retrospectively reviewed. The location, MR signal intensity, restricted diffusion, enhancement pattern and reversibility from the follow up images were reviewed. Clinical features were reviewed with respect to the presented symptoms, signs, treatment and outcome. Results: The lesions were located in the splenium of corpus callosum in all patients. All lesions showed high signal intensity on diffusion weighted imaging (DWI), and six patients showed restricted diffusion on the apparent diffusion coefficient (ADC) map. ADC map was not available in one patient. All lesions (n = 7) showed high signal intensity on the T2 weighted image (T2WI). Five of the patients (71.4%) with follow up images (range 7 - 34 days) showed complete resolution of focal high signal intensity on DWI, with recovery of ADC values as well as T2WI. After contrast media administration, none of the lesions showed any enhancements. All lesions with various etiologies including TB medication were developed in younger age patients and showed reversibility after the acceptable period of minimum 7 days with conservative treatment. Conclusion: All TSL showed nonspecific imaging findings, including restricted diffusion on DWI and ADC map on the initial images. However, reversibility of the lesions and the young age preference can be a characteristic finding of TSL with acceptable period of minimum 7 days. In addition, to keep it in mind that various etiologies including TB medication may cause TSL, is important for radiologists as well as clinicians.

• The Korean Journal of Nuclear Medicine
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• v.35 no.6
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• pp.364-370
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• 2001

Purpose: In the revascuarization of ischemic dysfunctional myocardium, stunned myocardium was reported to recover function earlier than hibernating myocardium. It was also suggested that stunning and hibernation could be discriminated by reversibility of perfusion impairment on myocardial SPECT. In this study, we investigated the time course of functional recover after CABG according to reversibility of perfusion impairment. Materials and Methods: In 92 patients with coronary artery disease, Tl-201 rest/dipyridamole stress Tc-99m-MIBI gated SPECT was performed before, 3 months after, and 17 months after CABG. Using a 20-segment model, segmental perfusion and systolic thickening were automatically quantified. Perfusion-impaired segments with abnormal thickening were classified by reversibility into reversible (REV) and irreversible (IRREV) groups. The proportions of function-recovered segments were compared between groups and also between 3 months and 17 months in each group. Results: A total of 129 segments were Included In the analysis, and 76 were REV and 53 were IRREV. At 3 months after CABG, 61 segments (80%) in REV group showed functional recovery while 28 segments (53%) in IRREV group did (p<0.001). However, at 17 months after CABG, 60 segments (79%) in REV group and 37 segments (70%) un IRREV group showed functional recovery (p=n.s.). When comparing 3 months and 17 months in each group, REV group showed no difference, while IRREV group showed significant further improvement (p<0.05). Conclusion: In viable myocardium with ischemic myocardial dysfunction, the segments with reversible perfusion impairment recover function earlier after revascularization than irreversible segments.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.1020-1028
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• 2012

This work compares various models for geminate reversible diffusion influenced reactions. The commonly utilized contact reactivity model (an extension of the Collins-Kimball radiation boundary condition) is augmented here by a volume reactivity model, which extends the celebrated Feynman-Kac equation for irreversible depletion within a reaction sphere. We obtain the exact analytic solution in Laplace space for an initially bound pair, which can dissociate, diffuse or undergo "sticky" recombination. We show that the same expression for the binding probability holds also for "mixed" reaction products. Two different derivations are pursued, yielding seemingly different expressions, which nevertheless coincide numerically. These binding probabilities and their Laplace transforms are compared graphically with those from the contact reactivity model and a previously suggested coarse grained approximation. Mathematically, all these Laplace transforms conform to a single generic equation, in which different reactionless Green's functions, g(s), are incorporated. In most of parameter space the sensitivity to g(s) is not large, so that the binding probabilities for the volume and contact reactivity models are rather similar.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2007.02a
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• pp.127-133
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• 2007

We propose new reversible watermarking method for images. Being reversibility, original image and watermarked message should be recovered exactly. We propose different technique for hiding data to pairs. We use new type of histogram (pair histogram), which shows frequencies of each pair in image. We use histogram shift method for data embedding to pairs. We also propose improved version of method which allow hiding data with good performance for high capacities. This algorithm has better result compare to Tian's difference expansion method based on the Haar wavelet decomposition. For proposed algorithm capacity is higher under same PSNR.

• Journal of Chest Surgery
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• v.19 no.2
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• pp.238-242
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• 1986

The prognosis of patients with VSD and pulmonary hypertension is at least partially related to the reversibility of pulmonary hypertension after surgery. To predict postoperative pulmonary arterial pressure, immediate postbypass values were compared with preoperative hemodynamic data in 18 surgically closed VSD patients aged 6 to 80 months. The following results were obtained. 2] There was a good correlation between preoperative PP/PS and postoperative PP/PS in patients aged over 24 months [r=0.685, p<0.05], and in patients whose QP/QS were over 2.0 [r=0.686, p<0.01]. 3] There was also a good correlation between pump time and postoperative PP in total patients [r=0.697, p<0.005]. 4] Direct correlations were found between preoperative PP/PS and immediate postbypass PP/PS in patients aged over 24 months and in patients whose QP/QS>2.0, but the effect of CPB would participate in some degree. So it may be necessary to reevaluate their relationship after the effect of CPB have been disappeared.

• Journal of Microbiology
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• v.42 no.3
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• pp.223-227
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• 2004

An ${\alpha}$-glucosidase inhibitor, SKG-3, was isolated from the fruiting bodies of Ganoderma lucidum and its physico-chemical properties were characterized. It was a highly specific and effective reversible inhibitor of ${\alpha}$-glucosidase. It showed very potent inhibitory activity against a-glucosidase with an IC$\sub$50/ value of 4.6$\mu\textrm{g}$/$m\ell$, but no activity for any other glycosidases tested. Enzyme activity could be recovered upon dialysis, thus providing evidence for the reversibility of the inhibition. A Lineweaver-Burk plot indicated that the SKG-3 inhibition of ${\alpha}$-glucosidase was competitive.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.512-517
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• 2007

In the previous development of the recursive thermostat chained fully flexible cell molecular dynamics simulation, implicit time integration method such as generalized leapfrog integration is used. The implicit algorithm is very much complicated and not easy to show time reversibility because it is solved by the nonlinear iterative procedure. Thus we develop simple, explicit symplectic time integration formula for the recursive thermostat chained fully flexible unit cell simulation. Uniaxial tension test is performed to verify the present explicit algorithm. We check that the present simulation satisfies the ergodic hypothesis for various values of fictitious mass and coefficient of multiple thermostat system. The proposed method should be helpful to predict mechanical and thermal behavior of nano-scale structure.