• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.389-390
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• 2012

In this study, we fabricate a superhydrophobic surface made of hierarchical nanostructures that combine wax crystalline structure with moth-eye structure using vacuum cluster system and measure their hydrophobicity and durability. Since the lotus effect was found, much work has been done on studying self-cleaning surface for decades. The surface of lotus leaf consists of multi-level layers of micro scale papillose epidermal cells and epicuticular wax crystalloids [1]. This hierarchical structure has superhydrophobic property because the sufficiently rough surface allows air pockets to form easily below the liquid, the so-called Cassie state, so that the relatively small area of water/solid interface makes the energetic cost associated with corresponding water/air interfaces smaller than the energy gained [2]. Various nanostructures have been reported for fabricating the self-cleaning surface but in general, they have the problem of low durability. More than two nanostructures on a surface can be integrated together to increase hydrophobicity and durability of the surface as in the lotus leaf [3,5]. As one of the bio-inspired nanostructures, we introduce a hierarchical nanostructure fabricated with a high vacuum cluster system. A hierarchical nanostructure is a combination of moth-eye structure with an average pitch of 300 nm and height of 700 nm, and the wax crystalline structure with an average width and height of 200 nm. The moth-eye structure is fabricated with deep reactive ion etching (DRIE) process. $SiO_2$ layer is initially deposited on a glass substrate using PECVD in the cluster system. Then, Au seed layer is deposited for a few second using DC sputtering process to provide stochastic mask for etching the underlying $SiO_2$ layer with ICP-RIE so that moth-eye structure can be fabricated. Additionally, n-hexatriacontane paraffin wax ($C_{36}H_{74}$) is deposited on the moth-eye structure in a thermal evaporator and self-recrystallized at $40^{\circ}C$ for 4h [4]. All of steps are conducted utilizing vacuum cluster system to minimize the contamination. The water contact angles are measured by tensiometer. The morphology of the surface is characterized using SEM and AFM and the reflectance is measured by spectrophotometer.

• Asian Pacific Journal of Cancer Prevention
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• 제15권19호
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• pp.8351-8359
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• 2014

Background: Recent epidemiological data have implicated human papilloma virus (HPV) infection in the pathogenesis of head and neck cancers, especially oropharyngeal cancers. Although, HPV has been detected in varied amounts in persons with oral dysplasia, leukoplakias and malignancies, its involvement in oral tongue carcinogenesis remains ambiguous. Materials and Methods: HPV DNA prevalence was assessed by PCR with formalin fixed paraffin embedded sections (n=167) of oral tongue squamous cell carcinoma patients and the physical status of the HPV16 DNA was assessed by qPCR. Immunohistochemistry was conducted for p16 evaluation. Results: We found the HPV prevalence in tongue cancers to be 51.2%, HPV 16 being present in 85.2% of the positive cases. A notable finding was a very poor concordance between HPV 16 DNA and p16 IHC findings (kappa<0.2). Further molecular classification of patients based on HPV16 DNA prevalence and p16 overexpression showed that patients with tumours showing p16 overexpression had increased hazard of death (HR=2.395; p=0.005) and disease recurrence (HR=2.581; p=0.002) irrespective of their HPV 16 DNA status. Conclusions: Our study has brought out several key facets which can potentially redefine our understanding of tongue cancer tumorigenesis. It has emphatically shown p16 overexpression to be a single important prognostic variable in defining a high risk group and depicting a poorer prognosis, thus highlighting the need for its routine assessment in tongue cancers. Another significant finding was a very poor concordance between p16 expression and HPV infection suggesting that p16 expression should possibly not be used as a surrogate marker for HPV infection in tongue cancers. Interestingly, the prognostic significance of p16 overexpression is different from that reported in oropharyngeal cancers. The mechanism of HPV independent p16 over expression in oral tongue cancers is possibly a distinct entity and needs to be further studied.

• 한국식품과학회지
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• 제30권2호
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• pp.260-265
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• 1998

참깨를 170, 200, $230^{\circ}C$로 열풍순환식과 전기팬에서 볶아서 참유한 기름의 향기 성분을 GC와 GC-MS로 분석하여 동정 확인하고 관능 검사를 실시하였다. 총 33개의 향기성분이 확인 되어졌으며 pyrazine류 14종, thiazole류 7종, pyridine류 4종, oxazole류 2종 및 기타 6종 이였다. 전기팬에서 170, 200, $230^{\circ}C$에서 처리된 시료의 총 향기성분의 함량은 각각 145.29, 334.65, 313.04 ppm 이였고 열풍순환식에서는 각각 28.86, 81.20, 313.28 ppm이 였다. 그리고 개별향기 성분중에서는 pyrazine류의 함량비가 가장 높았다. 6개의 시료에 대한 관능 검사의 결과는 $200^{\circ}C$에서 배전식 방법으로 볶은 참깨로부터 제조된 참기름이 가장 바람직한 향기를 가진것으로 판단되어졌다. 이런 현상은 GC 분석의 결과와 일치하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권2호
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• pp.99-107
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• 2020

Objectives: We accessed the various clinico-histopathological factors, and their association with occult metastasis (OM) in oral tongue squamous cell carcinoma (OTSCC). Materials and Methods: One hundred-nine patients with OTSCC were divided into the elective neck dissection (END) group and the watchful waiting (WW) group. Age, sex, T-stage, depth of invasion and differentiation were evaluated to determine the correlation between clinico-histopathological factors and OM. For immunohistochemical analysis, paraffin-embedded blocks of 41 OTSCC specimens were examined with antibodies (VEGF-c, c-Met, and ROR1). Results: The group with tumor thickness of oral tongue cancer ≥3 mm had higher incidence of OM than those with a thickness of <3 mm. The depth of invasion was statistically correlated with OM (P=0.022). Immunohistochemical analysis showed that high expression of VEGF-c (P=0.043), c-Met (P=0.009), and ROR-1 (P=0.003) were statistically correlated with OM. Conclusion: The analysis of these clinico-histopathological and immunohistochemical factors can help to determine neck dissection in clinically negative (cN0) patients.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3767-3771
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• 2015

Background: Lynch syndrome (LS) is an inherited predisposition to colorectal, endometrial (uterine) and other cancers. Although most cancers are not inherited, about 5 percent (%) of people who have colorectal or endometrial cancer have the Lynch syndrome. It involves the alteration of mismatch repair (MMR) genes; MLH1, MSH2, MSH6 or PMS2. In this study, we analyzed the expression of MMR proteins in colorectal cancer in a Malay cohort by immunohistochemistry. Materials and Methods: A total of 17 patients were selected fulfilling one of the Bethesda criteria: colorectal cancer diagnosed in a patient aged less than 50 years old, having synchronous and metachronous colorectal cancer or with a strong family history. Immunohistochemical staining was performed on paraffin embedded tumour tissue samples using four antibodies: MLH1, MSH2, MSH6 and PMS2. Results: Twelve out of 17 patients (70.6%) were noted to have a family history. A total of 41% (n=7) of the patients had abnormal immunohistochemical staining with one or more of the four antibodies. Loss of expression were noted in 13 tumour tissues with a negative staining score <4. Of 13 tumour tissues, four showed loss expression of MLH1. For PMS2, loss of expression were noted in five cases. Both MSH2 and MSH6 showed loss of expression in two tumour tissues respectively. Conclusions: Revised Bethesda criteria and immunohistochemical analysis constituted a convenient approach and is recommended to be a first-line screening for Lynch syndrome in Malay cohorts.

• Journal of Chest Surgery
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• 제51권3호
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• pp.187-194
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• 2018

Background: Death domain-associated protein (DAXX), originally identified as a pro-apoptotic protein, is now understood to be either a pro-apoptotic or an anti-apoptotic factor with a chromatin remodeler, depending on the cell type and context. This study evaluated DAXX expression and its clinical implications in squamous cell carcinoma of the esophagus. Methods: Paraffin-embedded tissues from 60 cases of esophageal squamous carcinoma were analyzed immunohistochemically. An immune reaction with more than 10% of tumor cells was interpreted as positive. Positive reactions were sorted into 2 groups: reactions in 11%-50% of tumor cells and reactions in more than 51% of tumor cells, and the correlations between expression and survival and clinical prognosticators were analyzed. Results: Forty-three of the 60 cases (71.7%) showed strong nuclear DAXX expression, among which 19 cases showed a positive reaction (31.7%) in 11%-50% of tumor cells, and 24 cases (40.0%) showed a positive reaction in more than 51% of tumor cells. A negative reaction was found in 17 cases (28.3%). These patterns of immunostaining were significantly associated with the N stage (p=0.005) and American Joint Committee on Cancer stage (p=0.001), but overall survival showed no significant difference. There were no correlations of DAXX expression with age, gender, or T stage. However, in stage IIB (p=0.046) and stage IV (p=0.014) disease, DAXX expression was significantly correlated with survival. Conclusion: This investigation found upregulation of DAXX in esophageal cancer, with a 71.7% expression rate. DAXX immunostaining could be used in clinical practice to predict aggressive tumors with lymph node metastasis in advanced-stage disease, especially in stages IIB and IV.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1973-1978
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• 2016

Background: Breast cancer is a heterogeneous disease that represents a major public health problem. The immunohistochemical determination of breast cancer subtypes with regard to estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2) status can contribute to improved selection of therapy and patientcare. The purpose of this study was to determine the prevalence of the molecular breast cancer subtypes and to assess their associations with classical clinicopathologic parameters for better therapeutic decisions in women with breast cancer in the Ivory Coast. Materials and Methods: Formalin-fixed and paraffin-embedded blocks of patients diagnosed with primary breast carcinoma were subjected to immunohistochemical assay for the assessment of ER/RP and HER2 expression. The one-way analysis of variance evaluated the difference between breast cancer subtypes and mean age of patients. The Chi-square Test was used to compare standard clinicopathologic prognostic parameters with tumor subtypes. Results. Among 302 patients, 57% were premenopausal and 43% were postmenopausal. The invasive ductal carcinoma not otherwise specified (IDC NOS) (82.8%) was the most frequent histological type, and the tumor grade 2 (56%) was predominant followed by grade 3 (20.9%). The proportion of positivity of ER, PR, and HER2 was 56%, 49%, and 15.6%, respectively. Half of patients of this study (51.6%) had luminal A breast tumor type followed by TN (32.1%). Other subtypes were luminal B (10.1% ) and non-luminal HER2+ (6.3%). Conclusions. The findings of the present study are in line with the literature and should assist in management of breast cancer in our country.

• Asian Pacific Journal of Cancer Prevention
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• 제16권4호
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• pp.1397-1401
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• 2015

Background: To determine the expressions of Tbx3, a member of subgroup belonging to T-box family, and its prognostic value in pancreatic carcinoma. Materials and Methods: We determined the expression levels of Tbx3 on both mRNA and protein levels in 30 pairs of fresh tumor tissues and paratumor tissues by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting, respectively. In addition, protein level of Tbx3 were identified using immunochemistry in 80 pairs of paraffin-embedded specimen. The correlations between Tbx3 expression and various clinicopathological parameters as well as overall survival were evaluated. Results: Tbx3 mRNA and protein levels in tumor tissues were significantly higher than in the paratumor tissues by qRT-PCR ($0.05{\pm}0.007$ vs. $0.087{\pm}0.001$, p<0.001) and western blotting ($1.134{\pm}0.043$ vs. $0.287{\pm}0.017$, p<0.001). The statistical analysis based on immunohistochemical evaluation suggested that Tbx3 aberrant expression was significantly associated with several conventional clinicopathological variables, such as gender, age, tumor position, preoperative CA19-9 level, pathological T staging and N staging. Univariate and multivariate analyses revealed that Tbx3 expression was an independent prognostic factor for overall survival (<0.001). Conclusions: Our results suggest that overexpression of Tbx3 is associated with poor prognosis of pancreatic cancer patients. However, additional clinical trials are needed to accurately validate this observation.

• 한국가금학회지
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• 제28권1호
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• pp.69-76
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• 2001

Avian primordial germ cells (PGCs) originate from the epiblast and appear in the germinal crescent. These PGCs enter the developing blood vessels during stage 10∼12 (H&H), circulate in the blood stream, migrate into the developing gonadal anlage and differentiate into germ cells. However, it is not clear until when the migratory ability of PGC is maintained. This study was conducted to examine whether migratory ability is present in PGCs from the gonad at later embryonic developmental stages. In the present study, gonads were dissected from 5-, 6- and 10-day old quail embryos and treated with trypsin-EDTA. Gonadal PGCs (gPGCs) were purified by Ficoll-density-gradient-centrifugation and labeled with PKH26 fluorescent dye. The PKH26-labeled gPGCs were microinjected into the blood vessel of the recipient quail embryo. Manipulated recipients were incubated for 3 days, embedded in paraffin and sdctioned. The foreign gPGCs were detected by fluorescent and confocal laser microscopy. As a result, quail gPGCs, from 10, 6 and 5 day old embryos could migrate through the recipient blood stream at early stage and settle in the gonads. Thus, results suggest that gPGCs from upto 10-day old embryos keep properties seen in circulating PGC. Therefore, the PGCs of 10-day old embryonic gonads can be used for the tools of genetic manipulation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제14권1_2호
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• pp.65-76
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• 1992

This study was designed to observe the adaptive changes of mandibular condyles to displacement of mandibular condyle in adult animals. In this study, 16 rabbits weighting about 3.5 kg was selected. Four rabbits were preserved for control group and 8 animals were divided into 3 groups, 2 weeks, 4 weeks and 8 weeks. The experimental animals were performed oblique osteotomy on both mandibular ramus and internal wiring at mandibular border. The experimental animals were sacrificed consecutively on the 2 weeks, 4 weeks and 8 weeks after oblique osteotomy and mandibular condyles were dissected out carefully to produced tissue specimen. The specimens were fixed with 10% N formaline solution for 24 hours and rinsed with phosphate buffer solution. It was decalcified with 5% nitric acid for 15 days. Thereafter the specimens were dehydrated in alcohol series and embedded paraffin as usual manner. The mebedded specimen were sectioned in $4-6{\mu}m$ microtome, stained with hematoxylin-eosin and azan stain and observed through light microscope. The following results were observed from this experiment. When there was postional change of condyle head after mandibular ramus oblique osteotomy in adult rabbit, 1. The density of chondrocyte was generally increased at condylar cartilage and the thickness of condylar cartilage was increased posterosuperior aspect of the mandibular condyle slightly. 2. The density of chondrocyte was increased at proliferative zone so fibrous articular zone, porliferative zone and hypertrophic zone was clearly distinguished. 3. Active endochondral bone formation was occurred at mandibular condyle.