• Restorative Dentistry and Endodontics
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• 제38권1호
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• pp.11-20
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• 2013

Objectives: In most retrospective studies, the clinical performance of restorations had not been considered in survival analysis. This study investigated the effect of including the clinically unacceptable cases according to modified United States Public Health Service (USPHS) criteria into the failed data on the survival analysis of direct restorations as to the longevity and prognostic variables. Materials and Methods: Nine hundred and sixty-seven direct restorations were evaluated. The data of 204 retreated restorations were collected from the records, and clinical performance of 763 restorations in function was evaluated according to modified USPHS criteria by two observers. The longevity and prognostic variables of the restorations were compared with a factor of involving clinically unacceptable cases into the failures using Kaplan-Meier survival analysis and Cox proportional hazard model. Results: The median survival times of amalgam, composite resin and glass ionomer were 11.8, 11.0 and 6.8 years, respectively. Glass ionomer showed significantly lower longevity than composite resin and amalgam. When clinically unacceptable restorations were included into the failure, the median survival times of them decreased to 8.9, 9.7 and 6.4 years, respectively. Conclusions: After considering the clinical performance, composite resin was the only material that showed a difference in the longevity (p < 0.05) and the significantly higher relative risk of student group than professor group disappeared in operator groups. Even in the design of retrospective study, clinical evaluation needs to be included.

• Radiation Oncology Journal
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• 제35권2호
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• pp.129-136
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• 2017

Purpose: The concentration of capecitabine peaks at 1-2 hours after administration. We therefore assumed that proper timing of capecitabine administration and radiotherapy would maximize radiosensitization and influence survival among patients with locally advanced rectal cancer. Materials and Methods: We retrospectively reviewed 223 patients with locally advanced rectal cancer who underwent preoperative chemoradiation, followed by surgery from January 2002 to May 2006. All patients underwent pelvic radiotherapy (50 Gy/25 fractions) and received capecitabine twice daily at 12-hour intervals ($1,650mg/m^2/day$). Patients were divided into two groups according to the time interval between capecitabine intake and radiotherapy. Patients who took capecitabine 1 hour before radiotherapy were classified as Group A (n = 109); all others were classified as Group B (n = 114). Results: The median follow-up period was 72 months (range, 7 to 149 months). Although Group A had a significantly higher rate of good responses (44% vs. 25%; p = 0.005), the 5-year local recurrence-free survival rates of 93% in Group A and 97% in Group B did not differ significantly (p = 0.519). The 5-year disease-free survival and overall survival rates were also comparable between the groups. Conclusions: Despite the better pathological response in Group A, the time interval between capecitabine and radiotherapy administration did not have a significant effect on survivals. Further evaluations are needed to clarify the interaction of these treatment modalities.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권1호
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• pp.1-12
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• 2013

Purpose: Vascular endothelial growth factor (VEGF)-C and its tyrosine kinase receptor, VEGF receptor (VEGFR)-3 are recently known to have lymphangiogenic activities in various tumor types. In this study, we determined whether the expression of lymphangiogenic factors correlate with nodal metastasis or survival in a nude mouse model of oral squamous cell carcinoma (OSCC). Methods: Three OSCC cells (KB, SCC4, SCC9) were xenografted into the right mandibular gland of athymic nude mice. The mice were followed for tumor development and growth, and the mice were sacrificed when they had lost more than 20% of their initial body weight, or the diameter of the induced tumor exceeds 20 mm. After necropsy, the murine tumors were examined histologically and radiologically (micro-positron emission tomography computed tomography) for regional or distant metastasis. We performed immunohistochemical assays with anti-VEGF-C, VEGFR-3, CD105, and D2-40 antibodies. Immunofluorescence double staining for LYVE-1/CD31 was also performed. To quantify the VEGF-C and VEGFR-3 level in the cancer tissue, Western blotting was performed. Finally, we determined the correlation between the degree of expression of VEGF-C/VEGFR-3 and the mean survival time. Results: OSCC tumor cells into the mandibular gland of the nude mice successfully resulted in the formation of recapitulating orthotopic tumor. Tumor cells of the induced tumor did not express VEGF-C. VEGF-C/VEGFR-3 expression was mainly distributed in the endothelial cells of the stromal area. There were no correlation between the degree of expression of VEGF-C/VEGFR-3 and the mean survival time of mice injected with different OSCC cell lines. Conclusion: An recapitulating orthotopic model of OSCC in nude mice was established, which copies the cervical nodal metastasis of human OSCC. Overexpression of lymphangiogenic factors seems to have no effect on survival of hosts in this in vivo experiment.

• The Journal of Advanced Prosthodontics
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• 제4권1호
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• pp.18-23
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• 2012

PURPOSE. The purpose of this prospective study was to evaluate the effect of early loading on survival rate or clinical parameter of anodic oxidized implants during the 12- month postloading period. MATERIALS AND METHODS. Total 69 implants were placed in 42 patients. Anodic oxidized implants (GS II, Osstem Cor., Busan, Korea) placed on the posterior mandibles were divided into two groups, according to their prosthetic loading times: test group (2 to 6 weeks), and control group (3 to 4 months). The implant survival rates were determined during oneyear postloading period and analyzed by Kaplan-Meier method. The radiographic peri-implant bone loss and periodontal parameters were also evaluated and statistically analyzed by unpaired t-test. RESULTS. Total 69 implants were placed in 42 patients. The cumulative postloading implant survival rates were 88.89% in test group, compared to 100% in control group (P<.05). Periimplant marginal bone loss (T: $0.27{\pm}0.54$ mm, C: $0.40{\pm}0.55$ mm) and periodontal parameters showed no significant difference between the groups (P>.05). CONCLUSION. Within the limitation of the present study, implant survival was affected by early loading on the anodic oxidized implants placed on posterior mandibles during one-year follow-up. Early implant loading did not influence peri-implant marginal bone loss, and periodontal parameters.

• 한국환경복원기술학회지
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• 제14권2호
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• pp.21-32
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• 2011

The effects of high polymer on the seedling survival were investigated in three major turfgrasses. Twelve treatments were used in the study with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Turfgrass seedling survival rate was evaluated in creeping bentgrass (CB), Kentucky bluegrass (KB), and zoysiagrass (Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments. Seedling survival rates were variable in CB, KB, and Zoy according to mixing rates of SOA and WSP, being maximum 20.2% in differences. At 6 weeks after seeding, the survival rates ranged from 0.6 to 61.9% in CB, 4.2 to 75.3% in KB and 1.7 to 82.1% in Zoy. A pattern of seedling emergence varied with time among treatments influenced by WSP rates. A proper mixing rate of WSP is considered to be 5% for CB and 5 to 10% for KB and Zoy. In general, overall effect of WSP on seedling survival was clearly observed in the mixtures of sand 80% and SOA 20% in CB. The best result, however, was found from the mixture of sand 85% and SOA 15% in both KB and Zoy. When mixing sand with WSP, a proper rate of SOA is considered to be 20% for CB and 15 to 20% for KB, while 10 to 15% for Zoy. A further research is needed to investigate the effects of WSP on the turf quality in mixtures of sand, SOA, and WSP before a field application.

• 벤처창업연구
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• 제18권1호
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• pp.225-236
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• 2023

2015년~2021년 혁신인증을 획득한 혁신형 중소기업과 일반 중소기업에 대해 생존기간의 관점에서 비교·분석하여 정책적 시사점을 도출하였다. 업력, 규모(고용인원, 자본 및 부채, 매출액 및 영업이익), 한국표준산업분류 중분류를 이용하여 혁신형 중소기업과 유사한 일반 중소기업을 선별하였으며, 생존기간은 휴·폐업 및 부도에 준하는 연체를 사건으로 정의하여 산출하였다. 생존분석 결과 혁신형 중소기업은 일반 중소기업 대비 휴·폐업 및 연체 발생 위험이 9.8% 감소하는 것으로 나타나, 혁신형 중소기업의 생존기간이 유의하게 길다는 결론을 도출하였다. 그 외 중소기업의 업력과 규모(고용인원, 자본)는 생존기간에 정(+)의 영향을, 부채는 부(-)의 영향을 미치는 것으로 나타났다. 따라서 혁신역량과 미래성장성 중심의 혁신인증 제도는 생존기간의 관점에서 유의한 지표이며, 혁신인증 제도의 혜택 및 지원정책이 중소기업의 실질적 성장과 생존을 위해서는 업력 및 업종을 반영하여 보다 체계적이고 정교화 될 필요가 있다는 결론을 도출하였다.

• 약학회지
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• 제43권2호
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• pp.274-277
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• 1999

A study has been conducted to investigate the radioprotective effects of purslane extracts (P) when i.p. injected before irradiation (R). For studying the amino acid composition, three groups of ICR mice (7-week-old) were tested. The first group i.p. injected with purslane extract for 5 days were irradiated with 6 Gy of ${\gamma}$-radiation (P+R). The second group was irradiate with 6 Gy without any pretreatment (R). The third group was non-irradiated control (CT). Each group divided into two groups for the survival rate study, one injected with saline (S) and the other injected with purslane extract (P) for five days and then irradiated with 8 Gy. The amino acid composition of urine samples were analyzed with HPLC for 19 days after irradiation. A few kinds of amino acids such as lysine and methionine in urine from P+R group increased in comparison with those from CT or R group. The survival rate of P group maintained much higher than that of S group during experimental period. The results obtained may support that this plant has radioprotective substances by means of life-lengthening, not of urine amino acid components.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
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• pp.47.1-47
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• 2001

One of the problems associated with in vitro culture of primordial gern cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of the porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally, \ulcorner2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p<0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layer, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of \ulcorner2-macroglobulin and antioxidatns can increase the number of PGCs in vitro by suppressing apoptosis.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
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• pp.47-47
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• 2001

One of the problems associated with in vitro culture of primordial germ cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally,？ 2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p〈0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layers, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of ？2-macroglobulin and antioxidants can increase the number of PGCs in vitro by suppressing apoptosis.

• 대한종양외과학회지
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• 제14권2호
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• pp.116-119
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• 2018

Purpose: This study assessed the effect of chemotherapy over stage II colon cancer in terms of presence of high-risk factors. Methods: Data were retrospectively reviewed for 364 patients with stage II colon cancer who underwent curative surgery between January 2007 and December 2012. High-risk factors of stage II colon cancer were examined, and the overall survival (OS) rates were analyzed. Survival benefit of adjuvant chemotherapy was also analyzed. Results: One hundred and fifteen cases had exclusively single high-risk factor and 194 cases were negative for high-risk factors. Postoperative chemotherapy was performed in 262 of 364 patients (72.0%). The 5-year OS was 79.4% and 86.6% for patients without adjuvant chemotherapy and those with chemotherapy, respectively. The 5-year OS was 88.2% and 83.3% for patients having exclusively single high-risk factor with adjuvant chemotherapy and those without chemotherapy, respectively. Conclusion: Adjuvant chemotherapy for patients with stage II colon cancer having exclusively single high-risk factor could be omitted, weighing up the survival benefit and side effect of chemotherapy.