• The Korean Journal of Physiology
• /
• v.24 no.2
• /
• pp.363-375
• /
• 1990

The present investigation was performed to purify bombesin-like immunoreactivity (BBS-LI) from the skin of frogs, B. orientalis inhabiting Korea. For extraction of BBS-LI, the fresh skin of 360 g from frogs was immersed in 1,800 ml of 100% methanol and then kept at $4^{\circ}C$ for 5 days. BBS-LI was partially purified by liquid chromatography using an alkaline alumina column followed by a Sephadex G-10 column. BBS-LI was further purified by using sequential HPLC of reversed phase C18 preparation, gel permeation, SP-ion exchange and reversed phase C18 analysis. BBS-LI in fractions of each step was monitored by radioimmunoassay for which bombesin antiserum with a titer of 1 : 188,800 was raised in a guinea pig. Eventually, two different BBS-LI were successfully purified and each BBS-LI showed the following character. 1) BBS-LI was well separated into two peaks in SP-ion exchange HPLC. One (BBS-LI-K1) bound to the column while the other (BBS-LI-K2) did not. 2) BBS-LI-K1, 73.8% of total BBS-LI, was not differentiated from synthetic bombesin in reversed phase C18 analytical and gel permeation HPLC. 3) BBS-LI-K2, 26.2% of total BBS-LI, eluted later than synthetic bombesin in reversed phase C18 analytical HPLC, but it eluted with a retention time identical to that of synthetic bombesin in gel permeation HPLC. 4) The two forms of BBS-LI and synthetic bombesin identically stimulated gastrin release and pancreatic exocrine secretion including volume, protein output and amylase output in anesthetized rats. It is concluded from the above results that the skin of B. orientalis contains two different forms of BBS-LI which are very identical to bombesin immunologically and biologically. In comparison with synthetic bombesin containing 14 amino acid residues, the major form shows quite similar pattern in all HPLC used in the present study, but the minor form exhibits quite different pattern in SP-ion exchange and reversed phase C18 analytical HPLG.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.10
• /
• pp.4129-4133
• /
• 2014

Background: The objective was to study the effect of Scutellaria baicalensis Georgi ethanol extracts (SBGE) on immune and anti-oxidant function in U14 tumor-bearing mice. Materials and Methods: U14 tumor-bearing mice were randomly divided into eight groups: a control group, a cyclophosphamide (CTX) group, three dose groups of SBGEI (high, medium, low), and three dose groups of SBGEII (high, medium, low). After two weeks, the thymus and spleen weight indices of mice bearing U14 cervical cancer were calculated. Enzyme linked immunosorbent assays (ELISA) was used to determine the levels of serum IL-2, TNF-${\alpha}$, IL-8, and PCNA. MDA activity and SOD activity in plasma were measured with detection kits. Results: In the SBGE groups, thymus weight and spleen weight indices of U14 tumor-bearing mice were significantly higher than in the control group or CTX group (p<0.05). Compared to control group, the levels of serum IL-2 and TNF-${\alpha}$ in U14 tumor-bearing mice increased significantly, whereas the contents of serum IL-8 and PCNA decreased (p<0.05). The activity of SOD increased with the growing dose of SBGE, while the activity of MDA decreased significantly in the highe-rdose groups of SBGE. Conclusions: These findings suggested that SBGE, especially at high dose, 1000 mg/kg, showed significant immune and anti-oxidant effects infU14 tumor-bearing mice, which might be the mechanisms of SBGE inhibition of tumor growth.

• Membrane Journal
• /
• v.14 no.4
• /
• pp.263-274
• /
• 2004

The polymeric membrane, a component of battery devices such as Li-ion battery (LIB) and Li-polymer battery (LPB), is a typical material in which the carrier mobility dominates the battery performance. In this paper, the state-of-the-art of membranes for secondary battery is described in terms of membrane properties. Several prerequisites, which are related to stability of battery devices, are discussed to design and prepare suitable polymeric membranes. In addition, physical requirements of membranes and their measurement methods are described to develop applicable polymeric membranes in membrane preparation processes.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.14 no.4
• /
• pp.341-349
• /
• 2002

Heat and mass transfer characteristics of a surfactant-added LiBr-$H_2O$ solution flowing over a single horizontal tube were examined experimentally. The parameters considered were surfactant (2-ethyl-1-hexanol) concentration, solution temperature at the top of the tube and absorber pressure. Even with an amount of the surfactant below the solubility limit, heat and mass transfer performances were enhanced tremendously. The Nusselt and Sherwood numbers increased by about 70% and 340%, respectively, when 10 ppm of the surfactant was added. However, an excess amount of the surfactant in the solution did not bring a further enhancement. The absorption performance deteriorated when the non-condensable gases were extracted from the system (by a vacuum pump) since the vaporized surfactant was also extracted during the process. Therefore, it is desirable to add a sufficient amount of the surfactant (more than 10 ppm) to maintain high performance of absorption.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.6 no.2
• /
• pp.155-165
• /
• 1996

Growth of $LiNbO_3$ single crystal by Czochralski method was carried out to study the piezoelectric effects. Piezoelectric coefficients and elastic compliances of the $LiNbO_3$ single crystal were determined by the resonance method of length-extentional mode of bar resonator from the room temperature up to $100^{\circ}C$. Two dielectric constants of $LiNbO_3$ were also determined by measuring the capacitance of the plate specimen. Measured constants were piezoelectric coefficients $d_{15},d_{22},d_{31},d_{33}$ elastic compliances $s^E_{11},s^E_{33},2s^E_{13}+2s^E_{44},s^E_{14}$ and dielectric constants $K^T_{11},K^T_{33}$. As temperature increased, elastic compliances changed very slowly while piezoelectric coeffiecients and dielectric constant $K^T_{33}$ changed very rapidly. Electromechanical coupling constant of zyw ($45^{\circ}C$)-bar was as high as 0.51 in room temperature and nearly constant up to $1000^{\circ}C$. The increase of piezoelectric coefficients was mainly due to the increase of dielectric permittivity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.29 no.3
• /
• pp.142-147
• /
• 2017

Improvement of the enthalpy exchange element's energy efficiency is of current interest from anenergy-saving viewpoint. In this study, a LiCl-impregnated spacer was devised as a means to improve the performance of the enthalpy exchange element. Two samples were tested : one with and one without impregnated spacers of $338{\times}338{\times}380mm$ sizes with 2.0 mm channel spacing. The results showed that the temperature efficiencies of the two samples were approximately the same. The humidity efficiency, however, was strongly affected by the LiCl impregnation. The impregnated sample yielded a 9% higher humidity efficiency under cooling and the difference increased to 14% under aheating condition. It was anticipated that more moisture would beadsorbed on the LiCl-impregnated spacers, which was delivered to their roots and eventually to the air in neighboring channels. Separate moisture adsorption tests revealed that both the adsorption rate and the amount of the adsorbed moisture are higher for the LiCl-impregnated specimen.

• Journal of Acupuncture & Meridian Studies
• /
• v.11 no.6
• /
• pp.367-374
• /
• 2018

This study describes the reliability of pragmatic combinations of acupuncture points for lateral epicondylalgia (LE) as prescribed by physiotherapists who were experts in acupuncture. Raters (n = 14; 33-59 years) independently prescribed acupuncture points for 30 simulated human patients with LE who were surveyed via a printed questionnaire. The frequency and cooccurrence of acupuncture points prescribed for patients with lateral epicondylitis were assessed. Absolute agreement and Light's kappa (${\kappa}_{Light}$) with 95% confidence interval (CI) were used to quantify the interrater agreement. Raters prescribed 103 unique acupuncture points in different combinations with a median (min-max) of 5 (0-11) acupuncture points. The most prescribed acupuncture point was LI-11 (297 of 420; 71%), and the most common cooccurring acupuncture points were LI-11 and LI-4 (160 of 420; 38%). The absolute agreement for prescribing the acupuncture points ranged from 70% (point GB-20) to 0% (points LI-10, SP-6, LI-11, GB-34, LI-12, and LI-4). Point LR-3 showed the highest interrater reliability for prescribing the acupuncture points [${\kappa}_{Light}=0.112$, 95% CI = (0.055-0.194)], whereas point LI-4 showed the lowest reliability [${\kappa}_{Light}=-0.003$, 95% CI = (-0.024 to 0.024)]. These findings suggest that pragmatic prescriptions of acupuncture points for LE are unreliable among physiotherapists who are experts in acupuncture. Explicit, high-level evidence-based rules for prescribing and teaching combinations of acupuncture points for LE are warranted.

• Journal of Power Electronics
• /
• v.14 no.1
• /
• pp.135-142
• /
• 2014

In the design of battery chargers, limiting the output ripple current according to the manufacturer's recommendation is important for reliable service and extended battery life. Ripple components can cause internal heating of the battery and thus reduce the service life of the battery. Care must be exerted in the design of the switching converter for the charge application through the accurate estimation of the output current ripple value. This study proposes a method to reduce the output current ripple of the converter and presents a detailed analysis of the output current ripple of the DC-DC boost converter to provide a guideline for the design of the battery charger.

• Computers and Concrete
• /
• v.14 no.2
• /
• pp.163-174
• /
• 2014

Damping as a material property plays an important role in decreasing dynamic response of structures. However, very little is known about the evaluation and application of the actual damping of Fiber Reinforced Polymer Confined Reinforced Concrete (FRP-C RC) material which is widely adopted in civil engineering at present. This paper first proposes a stress-dependent damping model for FRP-C RC material using a validated Finite Element Model (FEM), then based on this damping-stress relation, an iterative scheme is developed for the computations of the non-linear damping and dynamic response of FRP-C RC columns at any given harmonic exciting frequency. Numerical results show that at resonance, a considerable increase of the loss factor of the FRP-C RC columns effectively reduces the dynamic response of the columns, and the columns with lower concrete strength, FRP volume ratio and axial compression ratio or higher longitudinal reinforcement ratio have stronger damping values, and can relatively reduce the resonant response.

• Journal of Power Electronics
• /
• v.14 no.6
• /
• pp.1243-1253
• /
• 2014

The phase inductance of a switch reluctance motor (SRM) is significantly nonlinear. With different saturation conditions, the phase inductance shape is clearly changed. This study focuses on the relationship between coefficient and current in an inductance model with ignored harmonics above the order of 3. A position estimation method based on the variable coefficient inductance model is proposed in this paper. A four-quadrant sensorless control system of the SRM drive is constructed based on the relationship between variable coefficient inductance and rotor position. The proposed algorithms are implemented in an experimental SRM test setup. Experimental results show that the proposed method estimates position accurately in operating two/four-quadrants. The entire system also has good static and dynamic performance.