• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.286-293
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• 2009

The implantable middle ear hearing devices(IMEHDs) have been developed to overcome the conventional hearing aid's problem(ringing effect caused by the acoustic feedback, cosmetic problem, etc.). In the IMEHDs, the vibrating transducer is a key component because its vibration enables to hear for hearing impaired people. The vibrating transducer is implanted on ossicular chain by surgical operation. The coupling status between implanted transducer and ossicular chain has an effect on delivering vibrating force from transducer to stapes. Noninvasive method is required to investigate the output characteristics of IMEHDs after implementation. Recently, emitted sound pressure measuring method of tympanic membrane is proposed to investigate the output characteristics of IMEHDs. However, the relationship between displacement of stapes and sound pressure by tympanic membrane was not cleared. In this paper, displacement of stapes and sound pressure by tympanic membrane were measured using the differential floating mass transducer(DFMT) that implanted on the ossicular chain of the human temporal bone and physical ear model. Through the experiments results, the relationship between displacement of stapes and sound pressure by tympanic membrane was investigated.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.15-21
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• 1995

To evaluate availability of cerebral radionuclide imaging for diagnosis of brain death, we examined 25 patients with a suspected clinical diagnosis of brain death. 8 patients were studied by $^{99m}Tc$ DTPA and 15 patients were studied by $^{99m}Tc$ HMPAO (Hexamethyl propyleneamine oxime). Seven patients with $^{99m}Tc$ DTPA studies revealed absence of cerebral blood flow and sagittal sinus activity. All of 15 patients with $^{99m}Tc$ HMPAO studies revealed complete absence of cerebral perfusion. The results of the cerebral radionuclide studies of brain death correlated with other clinical conditions, such as intracranial pressure(ICP), EEG, transcranial doppler sonography(TCDS), and neurologic examination. The ICP of 8 patients, who are confirmed by brain death with $^{99m}Tc$ HMPAO study are elevated in all cases. In conclusion, cerebral radionuclide imaging for diagnosis of brain death is available. $^{99m}Tc$ HMPAO imaging is unequivocal, easily interpreted, well reflect the physiologic state of increased ICP, and provides adequate assessment of posterior fossa activity. In addition, the SPECT imaging with $^{99m}Tc$ HMPAO produces more accurate results due to it's superiority of image contrast and proper localization of radiopharmaceutical distribution than conventional planar imaging.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.189-199
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• 1996

Myocardial ${\alpha}_1-adrenoceptors$ have been shown to mediate a biphaslc inotropic response that was characterized by a transient decline followed by a sustained increasing phase in guinea pig ventricular muscle. Recently one group reported that an ${\alpha}_1-adrenoceptors-induced$ intracellular $Na^+$ decrease is linked to fast $Na^+$ channel inhibition and another group reported that it is linked to $Na^+$-$K^+$ pump activation by ${\alpha}_{1b}-adrenoceptors$. But until now, its mechanism is not clear. Therefore, to see whether the $Na^+$channel or $Na^+-K^+$ pump is related to a decrease in intracellular $Na^+$ activity and/or the negative inotropic response, and which ${\alpha}_1-adrenoceptor$ subtype was involved in the decrease in intracellular $Na^+$activity by phenylephrine, we used conventional and sodium selective microelectrodes, and tension transducer to determine the effects of ${\alpha}_1-adrenergic$ stimulation on membrane potential, intracellular $Na^+$ activity, and twitch force in guinea pig ventricular muscles. $10^{-5}$ M Phenylephrine produced a slight hyperpolarization of the diastolic membrane potential, a decrease or increase in $a_N^i_a$, and a biphasic inotropic response. The negative inotropic response accompanied by a decrease in intracellular $Na^+$activity, whereas in muscles showing a remarkable positive inotropic response without initial negative inotropic effect was accompanied by an increase in intracellular $Na^+$ activity. The decrease in intracellular $Na^+$ activity was apparently inhibited by WB4101, an antagonist of the ${\alpha}_{1a}-adrenoceptors$. The decrease in intracellular $Na^+$ activity caused by phenylephrine was not abolished or reduced by a block of the fast $Na^+$ channels. $V_{max}$ also was not affected by phenylephrine. Phenylephrine produced an increase in intracellular $Na^+$ activity in the presence of a high concentration of extracellular $Ca^{2+}$ (in quiescent muscle) or phorbol dibutyrate, a protein kinase C activator(in beating muscle). These suggest that the ${\alpha}_{1a}-adrenoceptors-mediated$ decrease in intracellular $Na^+$ activity may be related to the protein kinase C.

• KSBB Journal
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• v.24 no.3
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• pp.312-320
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• 2009

Stable cell preservation is an essential factor in the regenerative medicine for cell therapies and transplantation of biologic materials. In this study, we studied to provide more stable hypothermic preservation by protection of cell damage during the preservation at $4^{\circ}C$. The result of searching for key components that have excellent efficacy in hypothermic preservation of cells, we have identified the fact that the hypothermic preservation adding protein hydrolysates such as yeast hydrolysate is far superior to others. All protein hydrolysates that are derived from animal, plant and microbe sources have superior efficacy, especially the peptides which have molecular weights under 10 kDa have the best efficacy among the components of protein hydrolysate. The protein hydrolysates prevented the decrease of ATP level in the cells caused by hypothermic environment and they inhibited the generation of ROS. Adding antioxidants and control agents of osmotic pressure were showed to have more superior efficacy in hypothermic preservation. Finally, KUL261 solution (DMEM/F12 1 : 1 medium, yeastolate 1%, $\alpha$-tocopherol $100{\mu}M$, dextran 2.5%), the preservation solution developed in this study, showed the best efficacy in both cell viability and cell growth more than other conventional preservation solutions. In conclusion, the improved hypothermic preservation solution that contains the protein hydrolysates as a key component provide the best preservation efficacy. It provides better efficacy than other preservation solutions and will contribute to both the development of regenerative medicine and global commercialization in this therapeutic field.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.3
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• pp.203-210
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• 2004

The purpose of this study was comparing the effectiveness in the topical applications of cyclosporine with that of steroid, the conventional and standard drug in the treatment of oral lichen planus. 21 patients with oral lichen planus were treated with cyclosporine (n=11) or steroid (n=10) by random allocations. They were recalled 2 weeks, 4 weeks, and 8 weeks after initial treatments. In each recall, the lesion size, clinical symptoms like pain or burning sensation, and side effects were evaluated. The differences of these measurements were compared and the effects of each drug were checked. In reticulation types, steroid showed higher effectivity than cyclosporine and this difference was significant statistically. But in erythema type lesions, either drug showed no significant recovery, statistically. However, the effect of cyclosporine was thought to be more effective. The pain of the lesions was significantly decreased by cyclosporine but not by steroid. The decrease of burning sensation was more dependant upon steroid than cyclosporine, but no statistical relationship could be found. There were no clinical side effects. There was limitation to draw in conclusion due to small pool of this study group. But with the results, this suggestion could be proposed that either drug might be superior to another in effectivity in a specific lesion type or patient symptom, so selection and usage of one drug in a specific case could be better than universal application of one drug in all cases.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.189-195
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• 2002

In the area of pediatric dentistry, several behavior modification techniques have been attempted to relieve young patients' dental fear. The use of audio-visual(AV) aids is one of them and is increasing. In this study, several patients' reactions to dental treatment have been investigated after using AV aids, including patients' sleep, movement, crying and overall behavior. The effectiveness of AV aids have also been investigated through patients' age, previous dental experience and daily exposure to TV or video. Thirty healthy children with Frankl behavior rating (+) or (-) were included in this study. The average age of the children was $52.9{\pm}12.7$ months and no statistical difference was found between the two groups. Thirty patients were equally divided into two groups. Group I(control) received dental treatment with the conventional tell-show-do while group II(AV) with tell-show-do and AV aids. All patients received only restorative dental treatment and received no extraction. Houpt behavior rating scale was used to evaluate patients' behavior during the dental treatment. As a result, there was no significant difference between the two groups in movement and crying. However, more patients in the AV group fell asleep during the dental treatment compared to the control group. Within the AV group, patients with previous dental experience, older age and frequent exposure to AV materials showed better overall behavior during the dental treatment as audio-visual aids were used for behavior management.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.3
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• pp.293-299
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• 1995

Objective: To investigate the effects of sperm morphology and their co-incubation with oocytes on the outcome of IVF and ICSI. Design: Strict morphology of washed sperm was assessed by Diff-Quick staining method before or after insemination. And the relationships between strict morphology and outcome (fertilization, embryo development and pregnancy) of IVF(with co-incubation) and ICSI (without co-incubation) were determined. Patients: Two-hundreds-and-sixty-three cycles of IVF and ninety-six cycles of ICSI were analyzed in order to clarify the influence of strict sperm morphology of spermatozoa on outcome of IVF and ICSI. These were divided into four groups. according to fertilization method and sperm morphology(Group 1: IVF, ${\geq}$12%, n:227; Group 2: IVF, <12%, n:36; Group 3: ICSI, ${\geq}$ 12%, n=48; Group 4: ICSI, <12%, n=48). Results: The fertilization rates of better morphology groups were higher than those of poor groups: Group 1(68.1%) > Group 2(62.1%), Group 3(78.1%) > Group 4(71.5%). There was no difference in embryo cleavage rates among four groups (>90%), Regarded with the good embryo rates, Group 1(56.8%) was significantly higher than Group 2(42.3%)(P<0.01), but there was no difference between Group 3(64.7%) and Group 4(61.2%). The pregnancy rates were also higher in better morphology groups as well as fertilization rates: Group 1(34.8%)> Group 2(16.7%)(p<0.05), Group 3(40.0%) > Group 4(23.0%)(p=0.08). Conclusion: Co-incubation with poor morphology sperm might adversely affect the quality of embryos. And strict sperm morphology may represent the ability to establish successful pregnancy. In short, the strict sperm morphology can be a good predictor of IVF and ICSI outcome.

• Journal of Life Science
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• v.26 no.9
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• pp.1088-1096
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• 2016

Despite that moderate hyperthermia can exert various antitumor activities such as direct cytotoxic effects on tumor cells, effects on tumor vasculatures and immunological effects, hyperthermia has been usually combined with radiotherapy or chemotherapy due to its limited efficacy in cancer treatment, showing some positive clinical benefits with generally well-tolerated side effects. Since heat shock responses itself can interfere with the anti-tumor effects of hyperthermia, not all of these studies might have demonstrated positive clinical outcomes in cancer patients. Therefore, the negative anti-tumor effect of hyperthermia should be reduced to enhance the effectiveness of hyperthermia. Although the responses to heat stress of tumor tissues containing vessels, immune cells, connective tissues as well as cancer cells, are very complicated, it is needed to study in the near future if some clinically available drugs, which can modulate heat stress responses, can improve the efficacy of hyperthermia in patients with cancer. In this review, the effect of clinical hyperthermia centered on non-invasive external hyperthermia using radiofrequency at moderate temperature will be discussed, since it is the state-of-the-art technology in the current clinical practice of hyperthermia, and a moderate operational temperature is used to increase the therapeutic effectiveness of conventional therapy without additional toxicity to normal tissues.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.117-121
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• 2001

White kidney bean, Phaseolus vulgaris, contains proteinaceous inhibitors of ${\alpha}-amylase$. Two inhibitors have been purified by conventional protein fractionation methods such as ethanol precipitation, ammonium sulfate fractionation, DEAE-Sephadex ion exchange chromatography and Sephadex G-100 gel chromatography. The inhibitors were purified as I-1 and I-2 based on their elution order from the DEAE-Sephadex column. The overall purification ratio were about 15.0 and 14.8 for I-1 and I-2, respectively. The molecular weights of purified ${\alpha}-amylase$ inhibitors were 50,000 and 45,000 determined by Sephadex G-100 gel filtration and SDS-polyacrylamide gel electrophoresis. They contain $17.6{\sim}17%$ of carbohydrate, $70{\sim}80%$ of protein. The carbohydrates were composed of glucose : xylose : mannose : N-acetylglucosamine (5 : 3 : 50 : 42).

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.403-409
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• 1996

Background : Pleural fluid collections may pose a difficult therapeutic problem. Complete drainage of complicated effusions or empyemas and reexpansion of atelectatic lung are important in obtaining a satisfactory clinical outcome. The usual approach to the diagnosis and treatment of patients with pleural effusion and empyema has been with needle thoracentesis and chest tube drainage. With chest tube drainage, technical difficulties and failures may occur as a result of improper tube drainage, particularly when there is a loculation or multiple and inaccesible collections. Fluoroscopic or sonographic guidance facilitates the proper tube insertion and drainage. Method : Twenty eight patients were required for tube drainage due to pleural fluid collections between January 1994 to February 1996. The author compared the results of drainage under applying each different method between blind chest tube insertion and image guided catheter insertion. Results : The conventional blind chest tube group comprised 14 patients; 6 empyema, 6 tuberculous effusion, and 2 parapneumonic effusion. The image guided catheter group of smaller french were composed of 14 patients; 2 empyema, 6 tuberculous effusion, 5 parapneumonic effusion, and 1 effusion of undetermined origin. Radiologic improvement with successful drainage was noticed in 79% with the blind chest tube group, whereas in 93% with the image guided catheter group. The complication with the latter method was unremarkable. Conclusion : Image guided catheter drainage was safe and highly successful in treating patients, not only with complicated effusion also with loculated empyema. Image guided catheter drainage offers an alternative in patients in whom closed drainage is required as the initial treatment.