• 자원리싸이클링
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• 제29권1호
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• pp.35-42
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• 2020

최근 인체 유해성이 높은 석면 함유 제품의 다량 폐기로 인해 석면 함유 폐기물(asbestos-containing waste: ACW)이 계속해서 발생하고 있으며, 매립지 부족 등의 이유로 석면 무해화 및 재활용 기술 개발이 요구되고 있다. 마이크로웨이브를 이용한 열처리는 석면 함유 폐기물 무해화에 가장 효율적인 방법이나 석면이 상온에서 마이크로웨이브를 흡수하지 않는 한계점을 가지고 있다. 본 연구에서는 상온에서 마이크로웨이브를 흡수하여 발열하는 무기 발열체인 SiC 플레이트 사이에 석면 함유 폐기물를 위치시킨 상태에서 마이크로웨이브 열처리를 진행하는 방법으로 석면 함유 폐기물를 무해화 하였다. 효율적인 열처리를 위하여 석면 함유 폐기물를 파쇄 및 분쇄 공정을 통해 분말화하여 무해화 열처리 실험을 진행 하였으며, 열처리 조건에 따른 무해화 특성을 파악하기 위하여 마이크로웨이브 열처리 온도와 시간 변수를 조절하였다. 열처리 후 석면 함유 폐기물는 XRD와 SEM을 이용한 결정구조 및 미세구조 분석을 통하여 무해화 특성을 분석 하였다. SiC 플레이트를 적용한 마이크로웨이브 열처리 방법은 단시간 내에 목표 온도까지 가열이 가능하며 최종적으로 1,200℃에서는 60분 이상, 1,300℃에서는 10 분 이상의 마이크로웨이브 열처리를 진행하였을 때 결정구조와 미세구조상에서 석면이 완전히 제거되는 것을 확인하였다.

• 대한금속재료학회지
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• 제50권4호
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• pp.316-323
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• 2012

The aim of this study is to investigate the effect of post heat treatment on bonding properties of roll cladded Ti/MS/Ti materials. First grade Ti sheets and SPCC mild steel sheets were prepared and then Ti/MS/Ti clad materials were fabricated by a cold rolling and post heat treatment process. Microstructure and point analysis of the Ti/MS interfaces were performed using the SEM and EDX Analyser. Diffusion bonding was observed at the interfaces of Ti/MS. The thickness of the diffusion layer increased with post heat treatment temperature and the diffusion layer was verified as having $({\epsilon}+{\zeta})+({\zeta}+{\beta}-Ti)$ intermetallic compounds at $700^{\circ}C$ and an $({\zeta}+{\beta}-Ti)$ intermetallic compound at $800^{\circ}C$, respectively. The micro Knoop hardness of mild steel decreased with post heat treatment temperature; however, those of Ti decreased at a range of $500{\sim}600^{\circ}C$ and showed a uniform value until $800^{\circ}C$ and then increased rapidly up to $900^{\circ}C$. The micro Knoop hardness value of the diffusion layer increased up to $700^{\circ}C$ and then saturated with post heat treatment. A T-type peel test was used to estimate the bonding forces of Ti/Mild steel interfaces. The bonding forces decreased up to $800^{\circ}C$ and then increased slightly with post heat treatment. The optimized temperature ranges for post heat treatment were $500{\sim}600^{\circ}C$ to obtain the proper formability for an additional plastic deformation process.

• 대한두경부종양학회지
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• 제5권1호
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• pp.31-38
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• 1989

The result of neutron therapy on head and neck cancer using KCCH -Cyclotron neutron which had been using from October 1986 to September 1989 in the Korea Cancer Center Hospital. Among the total of 27 patients the cases of malignant salivary gland tumor were 14 and the cases of advanced head and neck cancer of AJCC stage IV were 13. The local control rate was 80% in malignant salivary gland tumor and 46.2% in advanced head and neck cancer. The 2 year survival rate was 60% in malignant salivary gland tumor and 38.5% in advanced head and neck cancer. Although there was no significant difference in prognosis according to the pathologic types, squamous cell carcinoma revealed a pattern of poor prognosis. The major complication from the neutron therapy had developed 7.1% in malignant salivary gland tumor and 23.1% in advanced head and neck cancer. In conclusion, neutron therapy is superior in the treatment of malignant salivary gland tumor and also effective in the treatment of advanced head and neck cancer when it can avoid to treat some site of low tolerance.

• Carbon letters
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• 제11권3호
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• pp.184-191
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• 2010

Carbon nanotubes are unique tubular structures of nanometer diameter and large length/diameter ratio. The nanotubes may consist of one up to tens and hundreds of concentric shells of carbons with adjacent shells separation of ~0.34 nm. Multiwalled carbon nanotubes were synthesized by arc-discharge technique. MWCNTs were formed at the cathode deposit along with other carbonaceous materials like amorphous carbon, graphite etc. However, to get the best advantage of carbon nanotubes in various advanced applications, these undesired carbonaceous materials to be removed which is a challenging task. In the present study, various techniques were tried out for purifying MWCNTs such as physical filtration, chemical treatment and thermal annealing. SEM, FTIR, TGA and BET techniques were used to characterize the CNTs at various stages. Results shows that suitable chemical treatment followed by thermal annealing under controlled flow of oxygen gives the better route for purification of carbon nanotubes.

• BMB Reports
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• 제28권5호
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• pp.392-397
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• 1995

The effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on the intracellular $Ca^{2+}$ level was studied in NIH3T3 fibroblast cells. A reduction of the intracellular $Ca^{2+}$ level was observed after exposure to 300 ${\mu}m$ MNNG. However, the intracellular level of $IP_3$, a well-known regulator of $Ca^{2+}$ release from internal storage, was not changed by MNNG treatment. Instead, a reduction of the intracellular NAD level was observed. NAD as well as $IP_3$ stimulated intracellular $Ca^{2+}$ release from permeabilized cells. The treatment of 3-aminobenzamide, which inhibited the MNNG-induced reduction of the NAD level, also prevented the MNNG-induced decrease of the $Ca^{2+}$ level. Our data suggest that MNNG reduces the intracellular $Ca^{2+}$ level by NAD depletion in NIH3T3 cells.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1123-1127
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• 2016

Chemotherapy is the primary treatment for advanced and recurrent cervical cancer. To evaluate the survival outcomes of chemotherapy and the prognostic factors in this setting, we conducted a retrospective study by reviewing the medical records of advanced and recurrent cervical cancer patients treated with systemic chemotherapy at our institute between January, 2008 and December, 2014. One hundred and seventy-three patients met the criteria with a mean age of 50.9 years. 4.1% of them were HIV positive. The most common initial stage was stage IVB (30.1%) and the most common histology was squamous cell carcinoma (68.6%). Ninety-two (53.2%) patients were previously treated with concurrent chemoradiation with 53% developing combined sites of recurrence. The median recurrence free interval was 16.7 months. Cisplatin + 5 fluorouracil (5FU) (53.2%) was the most frequent first line chemotherapy followed by carboplatin + paclitaxel (20.2%) with an objective response of 39.3%. Seventy-two patients received subsequent chemotherapy. The median overall survival of all studied patients was 13.2 months. Only a recurrence free interval of less than 12 months was an independent prognostic factor for survival outcome. In conclusion, chemotherapy treatment for advanced and recurrent cervical cancer patients showed modest efficacy with a shorter recurrence free survival less than 12 months as a significant poor prognosis factor.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.4107-4112
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• 2012

4-Nitroquinoline 1-oxide (4-NQO) a potent oral carcinogen, widely used for induction of oral carcinogenesis, has been found to induce lipid peroxidation in vivo and in vitro. Green tea contains a high content of polyphenols, which are potent antioxidants. Thus green tea polyphenols (GTP) might be expected play a protective role against 4-NQO induced lipid peroxidation and bone marrow toxicity. In the present study, a dose of 200 mg of GTP/kg b.wt/day was given orally for a week, simultaneously animals received 0.2 ml of 0.5% 4-NQO in propylene glycol (5 mg/ml) injected intramuscularly for three times/week. Oxidants and antioxidants such as malendialdehyde (MDA) and thiols, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) were significantly decreased in 4-NQO induced animals except MDA, and these parameters were brought back to near normalcy on treatment with GTP. The results suggest that GTP treatment offers significant protection against 4-NQO induced lipid peroxidation and bone marrow toxicity and might be a promising potential candidate for prevention of mutations leading to cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4391-4394
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• 2016

Background: Platinum-based regimens are effective treatments for advanced non-small cell lung cancer (NSCLC), but the five-year survival rate is still less than 20%. One possible factor appears to be resistance involving polymorphisms in the CTR1 gene which plays an importance role in accumulation of platinum in the cytoplasm. Purpose: To establish both prevalence of CTR1 polymorphism and its impact on treatment related toxicity in Thai advanced NSCLC patients. Materials and Methods: Thirty-two advanced NSCLC participants received carboplatin and gemcitabine during January to June 2016 at King Chulalongkorn Memorial Hospital (KCMH) were recruited for analysis of the CTR1 rs12686377 genotype. These participants were planning to be treated with platinum-based chemotherapy for at least two cycles. Results: Allele frequency of CTR1 polymorphism $G{\rightarrow}T$ was found to be 25%. The results showed that genetic polymorphism at CTR1 rs12686377 was associated with emesis side effects (P = 0.020) and neuropathic symptoms (P = 0.010). In addition, hematologic side effects in terms of anemia also tended to be related to this polymorphism. Conclusions: This is the first study suggesting that polymorphism at CTR1 rs12686377 may be associated with toxicity from platinum-based regimens. Therefore, it could be a factor to aid in treatment decision-making.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3357-3360
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• 2012

Objective: This study was to present the survival of advanced cancer patients and explore the influence of various factors on survival time as well as survival rate. The results provide guidelines for clinical practice of cancer treatment. Methods: Follow-up of 674 advanced cancer patients was performed in a hospice. The median survival time and survival rate were calculated, and survival analysis was carried out. Results: The median survival time of all patients dying from cancer was 12.0 months and the average survival time was 25.1 months. The 1-year cumulative survival rate was $0.518{\pm}0.020$ and the 5-year cumulative survival rate was $0.088{\pm}0.012$. The following factors showed significant impacts on survival rate: gender, age, primary diagnosis, surgery and the time when pain appeared. Conclusions: The survival time of patients with advanced cancer was relatively short. Major approaches to extend the survival time include early detection, early diagnosis, effective surgical treatment, pain control, reasonable supply of nutrients and multiple interventions.

• 열처리공학회지
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• 제17권5호
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• pp.299-304
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• 2004

Influence of Ca addition on microstructure and room temperature mechanical properties has been studied for AZ31(Mg-3%Al-1%Zn-0.2%Mn)-(0~0.5)%Ca wrought alloys, based on experimental results from metallography, X-ray diffractometry and mechanical tests. Yield strength, ultimate tensile strength and hardness of the alloys increased remarkably with increasing Ca content, whereas elongation was deteriorated continuously. Microstructural examination revealed that Ca addition efficiently refined grains of ${\alpha}$(Mg) phase and that some of the Ca dissolved in ${\beta}(Mg_{17}Al_{12})$ precipitates. The former and the latter facts are thought to be responsible for improved strength and loss of ductility of the AZ31+Ca wrought alloys, respectively.