• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.153-157
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• 2016

Although the adenosine triphosphate (ATP) efflux pathway is thought to play a major regulatory role in RVD in some cells, including cholangiocarcinoma cells, the role of ATP in regulatory volume decrease (RVD) of normal cholangiocytes is not well defined. Thus, this study was conducted to investigate the role of extra cellular ATP and ATP pathways of BDCCs isolated from normal mice. Changes in cell volume of BDCCs were indirectly assessed by measurement of the cross-sectional area (CSA) by quantitative videomicroscopy. The relative CSA of BDCCs from normal mice increased with hypotonic maneuver to $1.20{\pm}0.02$ (n=20) within 10 min, but decreased to $1.06{\pm}0.03$ at 40 min. Administration of ATP, ATP hydrolase apyrase or the P2 receptor blocker suramin during RVD had no significant effects compared with untreated controls. In addition, treatment with the PKC inhibitors, Bisindolamide I and Ro 31-8220, during RVD had no significant effects when compared with untreated controls. These results indicate that unlike the results from cholangiocarcinoma cells, ATP plays no significant role in the RVD of normal mouse cholangiocytes.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.281-284
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• 2006

The resistive V dipole (RVD) is a V antenna with both arms loaded with the continuous Wu-King resistive profile. The RVD has many advantages for surface and subsurface probing, such as the ability to radiate a short pulse in a desired direction. The radiated pulse is simply related to the input pulse, e.g., derivative. In addition, it mostly eliminates the multiple reflections between the surface of the ground and the antenna because of its low radar cross section. The drawbacks of the RVD include the high input impedance and the difficulty in implementation. This paper presents ways to improve the accuracy and easiness of the implementation and to improve the low-frequency performance while maintaining the characteristics of the V antenna that are good for probing applications. The implemented antenna is used to form a bistatic radar to scan targets underground, and the result is imaged.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.7
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• pp.597-605
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• 2015

Negative impedance converter(NIC)-based non-Foster impedance matching is proposed for an electrically small antenna. The antenna considered in this work is a resistively loaded vee dipole(RVD) antenna, which has considerable reflection at the feed point because of its large negative input reactance. The non-Foster matching circuit built near the feed point consists of two-stage NIC circuit and a capacitor connected between the stages. The NIC is realized by using operational amplifiers(op-amps) and resistors. The circuit is designed by considering of the input impedance according to the finite open-loop gain of the practical NICs. The stability test of the impedance-matched RVD antenna is performed. The non- Foster matching circuit is implemented with the RVD antenna. The measured impedance demonstrates that the proposed non-Foster matching circuit effectively reduces the input reactance of the RVD antenna.

• Tuberculosis and Respiratory Diseases
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• v.72 no.4
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• pp.352-359
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• 2012

Background: The purpose of this study was to evaluate whether measuring the ratio of descending aortic enhancement (DAE) to main pulmonary artery enhancement (MPAE) on pulmonary computed tomography angiography (PCTA) can predict poor outcome in patients with acute massive or submassive pulmonary embolism (PE). Methods: We retrospectively, reviewed computed tomgraphy findings and charts of 37 patients with acute PE and right ventricular dysfunction. We divided the enrolled patients into 3 groups; group Ia (n=8), comprised of patients with major adverse event (MAE); group Ib (n=5), consisted of those with PE-related MAE; and group II (n=29), those without MAE. We analyzed the right ventricular diameter (RVD)/left ventricular diameter (LVD) and DAE/MPAE on PCTA. Results: For observer 1, RVD/LVD in group Ia ($1.9{\pm}0.36$ vs. $1.44{\pm}0.38$, p=0.009) and group Ib ($1.87{\pm}0.37$ vs. $1.44{\pm}0.38$, p=0.044) were significantly higher than that of group II. For observer 2, RVD/LVD in group Ia ($1.71{\pm}0.18$ vs. $1.41{\pm}0.47$, p=0.027) was significantly greater than that of group II, but RVD/LVD of group Ib was not ($1.68{\pm}0.2$ vs. $1.41{\pm}0.47$, p=0.093). For both observers, there was a significant difference of DAE/MPAE between group Ib and group II ($0.32{\pm}0.15$ vs. $0.64{\pm}0.24$, p=0.005; $0.34{\pm}0.16$ vs. $0.64{\pm}0.22$, p=0.004), but no significant difference of DAE/MPAE between group Ia and group II ($0.51{\pm}0.3$ vs. $0.64{\pm}0.24$, p=0.268; $0.53{\pm}0.29$ vs. $0.64{\pm}0.22$, p=0.302). Intra-class correlation coefficient (ICC) for the measurement of DAE/MPAE (ICC=0.97) was higher than that of RVD/LVD (ICC=0.74). Conclusion: DAE/MPAE measured on PCTA may predict PE-related poor outcomes in patients with massive or submassive PE with an excellent inter-observer agreement.

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.305-312
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• 1996

Cell volume regulatory mechanisms are usually disclosed by exposure of cell to anisotonic media. If a cell is suddenly exposed to hypotonic media, it swells initially like an osmometer but within minutes regains its original cell volume. This behavior has been labelled as regulatory cell volume decrease(RVD). RVD is believed to result from the loss of permeable ions through the membrane. In this study, we examined hypotonically induced changes in the membrance currents involved in RVD by using whole cell voltage clamp technique in the unfertilized hamster egg. At -40mV of the holding potential, the stationary current was maintained in the hamster egg exposed to isotonic solution composed of, mainly, 115mM NaCl and 40mM mannitol. Hypotonic solution was prepared by removing mannitol. Therefore, the concentrations of $Na^+$ and $Cl^-$ in this hypotonic media were the same as those in the isotonic solution. Following 30 to 60 sec after applying the hypotonic media to the egg, the inward current was evoked. This inward current was eliminated by $100{\mu}M$ 4-acetamido-4'-isothiocyanostil-bene-2,2'-disulfonic acid(SITS), an anion channel blocker, leaving the small outward current component. Further addition of 2mM $Ba^{2+}$, a broad $K^+$ channel blocker, completely abolished the small outward current left even in the presence of SITS during hypotonic stress. These results suggest that $K^+$ and $Cl^-$ move out of cells, resulting in RVD. To test the involvement of $Na^+$ in RVD, 20mM Na-isethionate was substituted for mannitol in isotonic media(135mM $Na^+$) and Na-isethionate (20mM) was freed the hypotonic solution. Only $Cl^-$ concentration in both isotonic and hypotonic media was kept constant at 115mM, whereas concentration of $Na^+$ was lowered in hypotonic solution to 115mM from 135mM in isotonic solution. Hypotonic medium induced the outward current in the egg equilibrated isotonically. This current was reduced by $100{\mu}M$ SITS but was augmented by 2 mM $Ba^{2+}$. In terms of RVD, these results imply that $Cl^-$ efflux is coupled with $K^+$, maybe for electroneutrality during hypotonic stress and/or with $Na^+$ via unknown transport mechanism(s). From the overall results, the hypotonic stress facilitates the movement of $Cl^-$ and $K^+$ out of the hamster egg to regain cellular volume with electroneutrality. If there exist a difference in $[Na^+]_0$ between isotonic and hypotonic solution, another transport mechanism concerned with $Na^+$ may, at least partly, participate in regulatory volume decrease.

• International Journal of Oral Biology
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• v.34 no.3
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• pp.151-155
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• 2009

The role of $Cl^-$ channels in regulatory volume decrease (RVD) in human salivary gland acinar cells was examined using a whole-cell patch clamp technique. Human tissues were obtained from healthy volunteers or from patients with oromaxillofacial tumors. During the measurements, $K^+$-free solutions were employed to eliminate contamination of whole-cell conductance by $K^+$ currents. When the cells were exposed to a 70% hypotonic solution, outward-rectifying currents, which were not observed in the resting state, were found to have significantly increased both in human labial and parotid gland acinar cells. The amplitudes of the currents were reduced in a low $Cl^-$ bath solution. Furthermore, the addition of $100{\mu}M$ 5-Nitro-2- (3-phenyl propylamino) benzoic acid (NPPB) or $100{\mu}M$ 4,4'-diisothio cyanatostilbene-2,2'-disulphonic acid (DIDS), known to partially block $Cl^-$ channels, significantly inhibited these currents. Its outward-rectifying current profile, shift in reversal potential in a low $Cl^-$ bath solution and pharmacological properties suggest that this is a $Ca^{2+}$-independent, volume activated $Cl^-$ current. We conclude therefore that volume activated $Cl^-$ channels play a putative role in RVD in human salivary gland acinar cells.

• Journal of Veterinary Clinics
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• v.36 no.4
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• pp.207-211
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• 2019

This study was performed to compare the radiographic and echocardiographic features of cardiovascular changes between small and large dogs with heartworm diseases. Total of 49 dogs from two institutions were included in this study. The dogs were diagnosed with heartworm infestation and underwent thoracic and echocardiography. On thoracic radiographs, vertebral heart scale, reverse D shape, main pulmonary artery dilation, peripheral pulmonary artery dilation, and evidence of right heart failure were evaluated. On echocardiographs, visibility of worms, main pulmonary artery to aortic root (MPA/Ao) ratio, right to left ventricular basal diameter (RVD/LVD) ratio, and pulmonary hypertension were evaluated and analyzed between small and large dogs. The proportion of reverse D shape of the heart and accuracy for right ventricular hypertrophy in small dogs were lower than those of the large dogs. For echocardiographic parameter, the MPA/Ao and RVD/LVD ratio in the small dogs were significantly lower than those of the large dogs. As the results, thoracic radiography have a tendency to underestimate the severity of HWD in small dogs and should be used with echocardiography.

• Korean Journal of Optics and Photonics
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• v.24 no.2
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• pp.77-85
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• 2013

The precision of retardation measurement has been improved upto $3{\sigma}$ <0.005 nm after improvements are made to the conventional transmission ellipsometer. Improvements are made such that, i) the polarizer module instead of the sample stage is rotated, ii) the light source is replaced, iii) the starting points of two rotating modules are accurately synchronized, and iv) the fine background retardation is compensated. Together with the newly introduced RVD (Retardation Vector Difference) method, the improved instrument is successfully applied to characterize the ultra small optical birefringence of the rubbed polyimide alignment layer, after the residual retardation due to glass substrate whose magnitude is about 1.0 nm is properly subtracted. It is verified that the net retardation of the alignment layer ranges from 0.05 nm to 0.15 nm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1157-1162
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• 2015

This paper is the design and implementation to the 4x4 MIMO algorithm based on OFDM, and presented how to verify the implemented result. Algorithm applied the MRVD and QRM-MLD. Matlab and Simulink are used to design channel presumption & MIMO algorithm by Floating-point and Fixed-point model. After then implement VHDL using Modelsim. Performance of algorithm is checked by comparing Simulink model, Modelsim simulation, ISE ChipScope with the result measured by oscilloscope. This method is useful to verify an algorithm with uncompleted system. Conformance between the result of ChipScope and the result of oscilloscope is confirmed, it could be applied on the Backhaul system.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.6
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• pp.577-585
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• 2015

We fabricated multi-scale such as macro-, micro-, and multi-scale wrinkles by using repetitive volume dividing (RVD) method and thermal curing process. Also wrinkle surface was modified with coating of a self-assembled monolayer (SAM). We measured the contact angle of each wrinkled surface, and observed the behavior of droplets on sloping surface. Through experimental study, we found out that the contact angle was much higher in case of multi-scale and SAM coated wrinkles. And micro-scale wrinkle showed a high contact angle comparing with that of macro-scale wrinkle. Dynamic behaviors of a water droplet like sliding velocity on diverse wrinkled surfaces were dependent on their static contact angles. These results showed that hydro-dynamic characteristics were changed depending on the wrinkle structure and the material forming the wrinkle. These dynamic characteristics can be utilized in bio-chip, microfluidics, and many others in order to control easily chemical reactivity.