• Journal of the Korean Society for Nondestructive Testing
• /
• v.25 no.5
• /
• pp.339-342
• /
• 2005

In long-period fiber grating (LPFG) to be made up optical fiber sensors, resonance coupling occurs between the forward-propagating core mode and cladding modes at the wavelength that satisfy the Phase matching condition. The resonance wavelength and the coupling strength depends strongly on the external environment like temperature, strain, and ambient index. These characteristics can be utilized for various applications as optical fiber sensors. fabrication of optical fiber gratings is typically based on the photosensitivity effect, i.e. the permanent change of the refractive index upon irradiation of the UV beam, and therefore, fabrication of the optical fiber with high phososensitivity is an important part of the research on optical fiber gratings. In this work, we measured the effort of to-doping of boron on the index difference between the core and cladding of the optical fiber and the sensitivity of the LPFC to the temperature and bending changes. We observed that the index difference between the core and the cladding decreased by $(1.69{\times}10^{-4}/SCCM)$ and the temperature sensitivity of the resonance wavelength shirt decreased by $(0.01145nm/^{\circ}C/SCCM)$. The dependence or the bending-induced changes or the transmission characteristics of LPFG on the tore-cladding index difference was investigated experimentally. The measurement results indicate that the bending sensitivity increases as the index difference decreases.

• Radiation Oncology Journal
• /
• v.13 no.1
• /
• pp.55-61
• /
• 1995

Purpose : Despite a development of therapeutic machines and advance in modern radiation therapy techniques, locally advanced cervical carcinoma has shown high rate of local failure and poor survival rate, Combination of chemotherapy and radiotherapy demonstrated benefit in improving local control and possibly the overall survival. Our study was performed to evaluate effect of concurrent chemoradiation on locally advanced uterine cervical cancer. Methods and Materials : Twenty six patients with locally advanced stage(FIGO stage IIB with ${\geq}5cm$ in diameter, III, IVA) were treated with combination of radiation therapy and concurrent cisplatinum between May of 1988 and September of 1993 at our hospital. Radiation therapy consisted of external irradiaton and 1-2 sessions of intracavitary irradiation. Cisplatinum was administered in bolus injection of 25mg/$m^2$ at weekly intervals during the course of external radiation therapy. Results : Of the 26 Patients, twenty-five patients were evaluable for estimation of response. Median follow-up period was 25 months with ranges from 3 to 73 months. Stage IIB, III, and IVA were 16, 5, 4 patients, respectively, Twenty patients were squamous cell carcinoma. Response was noted in all 25 patients: complete response(CR) in 17/25($68\%$), Partial response(PR) in 8/25($32\%$). Of the 24 patients except one who died of sepsis at 3 months follow-up, seventeen patients($70.8\%$) maintained local control in the pelvis: 16/17($94.1\%$) in CR, 1/17($14.3\%$) in PR. Fourteen of the 17 patients with CR are alive disease free on the completion of follow-up. Median survival is 28 months for CR and 15 months for PR. Analysis of 5-year survival by stage shows 11/16($59.8\%$) in IIB, 3/5($60.0\%$) in III, and 1/4($25.0\%$) in IVA. Overall 5-year survival rate was $55.2\%$. Ten patients recurred: 4 at locoregional, 3 in distant metastasis and 3 with locoregional and distant site. Toxicity by addition of cisplatinum was not excessive. Conclusion : Although the result of this study was obtained from small number of patients, it is rather encouraging in view of markedly improved response rate compared with the results of historical group.

• Journal of Oral Medicine and Pain
• /
• v.24 no.4
• /
• pp.397-410
• /
• 1999

In order to obtain the basic data concerning the optimal parameters in using Nd:YAG laser as a therapeutic modality to dentinal hypersensitivity, the author prepared 3 sections of sound dentin and 10 sections of sclerotic dentin with thickness of $0.5mm{\pm}0.1mm$ from human extracted teeth of anteriors and premolars, and applied the laser energy from a fiberoptic delivered, free running, pulsed Nd:YAG laser (wavelength 1064nm, pulse duration $120{\mu}sec$, fiber diameter $320{\mu}m$) to surfaces of sound and sclerotic dentin sections for 1 second with contact/unidirectional moving mode of the fiber under speed of 3mm~4mm/sec and parameters of 0.5W/10Hz, 1.0W/10Hz, 1.5W/10Hz, 2.0W/10Hz: $62J/cm^2$, $124J/cm^2$, $187J/cm^2$, $249J/cm^2$. The author comparatively evaluated the characteristics of ultrastructural changes on surfaces of sound and sclerotic dentin sections irradiated by the pulsed Nd:YAG laser using the scanning electron microscopy. A fairly ill-defined bordered surface of partially closed and melted dentinal tubules can be seen on the scanning electron microscopic feature of the sound dentin surface irradiated by the pulsed Nd:YAG laser with energy density of $62J/cm^2$. The physical modification of sound dentin surface extensively occurred depended on the increase of energy density from $62J/cm^2$ to $124J/cm^2$, $187J/cm^2$, $249J/cm^2$. While, a fairly well-defined bordered surface of partially closed and melted dentinal tubules with thickened peritubular dentin can be seen on the scanning electron microscopic feature of the sclerotic dentin surface irradiated by the pulsed Nd:YAG laser with energy density of $62J/cm^2$. The physical modification of sclerotic dentin surface of a fairly rough, shallow depression with many cracks, thickened peritubular dentin and structureless dentinal tubules extensively occurred depended on the increase of energy density from $62J/cm^2$ to $124J/cm^2$, $187J/cm^2$, $249J/cm^2$ compared to those of sound dentin surface irradiated by the pulsed Nd:YAG laser under the same parameters. Therefore, it is recommended that the pulsed Nd:YAG laser as a therapeutic modality to dentinal hypersensitivity should be applied with the less energy density than $62J/cm^2$ on the sound dentin surface, and its energy density on the partially sclerotic dentin surface should be lower than that on the sound dentin surface to preserve tooth from unnecessary excessive structural destruction.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.2
• /
• pp.245-252
• /
• 2011

The combined effects of 10 kJ/$m^2$ ultraviolet-C (UV-C) with 50 ppm aqueous chlorine dioxide ($ClO_2$) on the qualities of red chicory and pak choi were examined. After the treatment, the samples were stored at $4{\pm}1^{\circ}C$ for 7 days. The combined treatment of $ClO_2$/UV-C reduced the initial populations of total aerobic bacteria in the red chicory and pak choi by 2.64 and 2.55 log CFU/g, respectively, compared to those of the control. Also, the populations of yeast and molds in the red chicory and pak choi by combined treatment were reduced by 2.41 and 2.00 log CFU/g, respectively. In addition, after 7 days of storage the total aerobic bacteria populations in the red chicory and pak choi were reduced to 3.71 and 3.93 log CFU/g, compared to 6.31 and 6.62 log CFU/g for the control, resulting in a significant decrease. Hunter L, a, and b values of red chicory and pak choi were not significantly different among the treatments. Non-thermal treatment caused a negligible change in sensory evaluation. These results suggest that the combined treatment of 50 ppm $ClO_2$ with 10 kJ/$m^2$ UV-C can be useful for maintaining the qualities of red chicory and pak choi.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.18 no.4
• /
• pp.351-354
• /
• 1998

Centipedegrass (Eremochloa ophiuroides) is a popular lawn grass in the southeastern USA. It has a naturally light green color and grows well on a wide range of soil types. Studies show limited morphological variation present in centipedegrass germplasm. To obtain the high morphological variation, plants were established from the irradiated seed at 10 Kr, allowed to interpollinate and harvested bulk seed, and then irradiated again for the next cycles. Morphological characteristics were measured in the 5 genetic varition lines (TC201 : cv. Common and non irradiated, TC202 : 4th cycles, TC241 : 6th cycles, TC306 : 8th cycles, and TC318 : 5th cycles) induced by recurrent gamma radiation. The ranges of variation of recurrently radiated centipedegrass lines < TC202, TC241 and TC306 except TC318(TifBlair) > for the stolons per plant, total stolon length per plant, longest stolon length, leaf length and width at top-most exposed internode were wider than those of non-irradiated line (TC201). Recurrent gamma radiation was very effective to enlarge the ranges of variation of morphological characteristics in reproductive organ like stolons of centipedegrass. The effect of quantity of gamma ray irradiation cycles on the means and ranges of variation in the morphological characteristics of centipedegrass was not regularly tended.

• Korean Journal of Head & Neck Oncology
• /
• v.22 no.2
• /
• pp.130-136
• /
• 2006

Introduction : The sensitivity of tumor cells to radiotherapy is a critical determinant of local control and potential cure in advanced head and neck squamous cell carcinoma(HNSCC). The emergence of radioresistant tumor cells is an obstacle to cancer therapy. Most radioresistant cells have a higher proportion of cells in the Sphase of the cell cycle and a lower apoptotic fraction than radiosensitive cells. HSV replication is increased in cells that have higher S-phase fractions. NV1066 is an oncolytic herpes simplex virus type-1 mutant. We hypothesized that NV1066 replication and cytotoxicity are increased in radioresistant cells. The purpose of this study is to evaluate the antitumor efficacy of NV1066 to treat radioresistant HNSCC. Methods : Radioresistant cells were selected by treating five HNSCC cell lines with repeated conventional fractionated doses of radiation(2Gy/day), using a Cs-137 irradiator, up to a cumulative dose of 70Gy. Clonogenic cell survival and S-phase fractions were compared between radioresistant and parental radiosensitive cells. The two cell populations were then treated with NV1066 to examine viral replication, by the viral plaque assay and viral cytotoxicity. Results : Fractionated irradiation resulted in the selection of radioresistant cells. Radioresistant cells had a higher S-phase fraction(42.9%) compared to parental cells(26.2%). NV1066 replication in radioresistant cells was 7.4 times higher than in parental cells(p<0.01). Treatment with NV1066 resulted in increased cytotoxicity of 24.5% in radioresistant cells compared to parental cells(p<0.05). Conclusion : NV1066 showed increased viral replication and cytotoxicity in radioresistant HNSCC cell lines. These findings suggest a potential clinical application for this oncolytic viral therapy as treatment for radioresistant head and neck cancers.

• Applied Chemistry for Engineering
• /
• v.26 no.2
• /
• pp.165-172
• /
• 2015

Quercetin and its glycoside, rutin, are flavonoids, which are well known as natural antioxidants. In this study, cationic liposomes loaded with flavonoids (quercetin or rutin) were investigated for their effects on cell and skin permeability, and protective effects against UVA. The particle size of the empty cationic liposomes was in the range of 100~130 nm, and the zeta potential was + 33.05 mV. The entrapment efficiency of 0.5R/CL was higher than that of 0.5 Q/CL. The cellular uptake of the cationic liposomes was five-fold higher than that of liposomes. The skin permeability of quercetin and rutin was investigated using Franz diffusion cells. Compared to the initial loading dose, the amount of quercetin or rutin delivered to the skin by cationic liposomes was higher than that delivered by conventional liposomes or phosphate-buffered saline. From the protective effect of cationic liposomes against UVA ($25J/cm^2$), we found that the cell viability in cationic liposomes containing flavonoids was higher than that of using UVA irradiation only. These results indicate that cationic liposomes provide enhanced delivery of flavonoids (quercetin and rutin) into the skin and may be used for antiaging and antioxidant cosmetics.

• Biomolecules & Therapeutics
• /
• v.6 no.1
• /
• pp.37-44
• /
• 1998

This study was performed to examine the effects of DA-9601, a novel antiulcer agent extracted from Artemisiae Herba, on radiation colitis in the rat. Female Wistar rats received a 30 Gy dose of irradiation to the 2 cm of distal colon in length using an intrarectal applicator system. 30 mg/tg or 100 mg/kg of DA- 9601 was administered orally 30 min before and 4 h after radiation on day 1. And the same dose of DA-9601 was given to the animals twice a day from day 2 to 14. As a reference control, sucralfate suspension (100 or 300 mg/head) was given as an enema based on the same treatment schedule of DA-9601. Body weight change and the frequency of diarrhea were recorded during the observation period as markers of radiationinduced injury, All animals were sacrificed on day 15 for evaluation of macro- and microscopic findings and mucosal myeloperoxidase (MPO) activity. Radiated animals showed diarrhea, mucosal redness and histologic changes characterized by edema and eosinophilic infiltration of the periglandular lamina propria with loss of colonic epithelium. Radiation also significantly increased mucosal MfO activity of affected colon f\\\\\\\\`<0.05). However, most of these changes were completely protected by oral administration with DA-9601. DA-9601 reduced radiation-induced histologic alteration significantly in a dose-related manner (P<0.05). In addition, mucosal MPO activity in rats receiving high dose of DA-9601 decreased significantly when compared with that in radiated control. High dose of sucralfate (300 mg/head) alleviated radiation-induced histologic lesion, but failed to reach statistical significance. The results of this study suggest that DA-9601 can be useful for the prevention of acute clinical symptoms of radiation proctocolitis and that decrease of mucosal MPO by DA-9601 plays a role in its protective mechanism(s), at least in part.

• Radiation Oncology Journal
• /
• v.10 no.2
• /
• pp.237-245
• /
• 1992

Five hundred and fifty patients treated for carcinoma of the uterine cervix at the Department of Therapeutic Radiology, Seoul National University Hospital from 1979 to 1986, were analyzed retrospectively for late rectal complications. Of them, 468 patients received primary radiotherapy for the cervix cancer in intact uterus, and the other eighty two patients were treated postoperatively. The cumulative incidence of radiation induced rectal complication of grade 2 or 3 was 6.7% at five years. The mean rectal dose for the group of patients with complication was higher than the group without complication, and the difference was statistically significant (p<0.01). But relationship between mean rectal dose and severity of complication was not found. The frequency of complication (grade 1, 2, 3) increased as a function of radiation dose to rectum; from 16.1% for patients with rectal dose less than 6,000 cGy to 71.2% for patients with rectal dose higher than 8,000 cGy. Among various factors analyzed, history of diabetes mellitus, number of intracavitary irradiation, size of ovoid, retroflexion of uterus and the total dose delivered to rectum turned out to have significant effect on the complication.

• The Korean Journal of Nuclear Medicine
• /
• v.30 no.3
• /
• pp.351-360
• /
• 1996

Chitosan is a polysaccharide of natural orgin obtained by full or partial deacetylation of chitin, a very abudant natural polymer, which has the properties of biocompatibilities, bioaffinities, and biodegradabilities. The free amino group of chitosan should be participated in forming chelate with holmium (${\beta}$-emitter). $^{166}Ho(NO_3)_3\;5H_2O$ of high radionuclidic purity of upto 99.9% was made by neutron irradiation of naturally occuring $^{166}Ho(NO_3)_3\;5H_2O$, and then reacted with the prepared chitosan solution. The effect of pH, reaction time, the concentration and viscosity of chitosan and the amount of $^{166}Ho$ on forming $^{166}Ho$-chitosan complex ($^{166}Ho$-CHICO) were investigated. $^{166}Ho$-chitosan macroaggregate($^{166}Ho$-CHIMA) was made from $^{166}Ho$-CHICO. Their physical properties such as radionuclidic purity, particle size distribution, stability in vitro and vivo were examined. Their high in vitro and vivo stability makes them attractive agents for internal radiotherapy by local administeration.