• Resources Recycling
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• v.32 no.6
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• pp.67-78
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• 2023

The rare metals used as raw materials in high-tech industries undergo changes in demand structures and supply chains following domestic industrial structural shifts and technological advancements, exhibiting high price volatility. Therefore, it is necessary to periodically analyze changes in the demand structures of rare metals. Since domestic demand for most rare metals relies on imports in Korea, the changes in domestic demand for rare metals can be identified by analyzing changes in their trade structure. In the present study, we analyze the changes in trade volume, trade growth rate, trade rankings, and trading countries from 2000 to 2022 for 35 rare metals, categorized into five types-ores, metals, alloys, compounds, and scrap. The trade of the raw materials of rare metals in Korea has generally increased since the 2000s, except for a significant decline in 2009 and 2016. The total trade volume, encompassing both exports and imports, has increased by approximately tenfold in 2022 compared to 2001. Until the mid-2010s, the trade of the raw materials of rare metals was primarily focused on those used in steel-manufacturing such as silicon, nickel, chrome, molybdenum, manganese, and others. However, after that period, there has been an increase in the trade of platinum group metals like palladium, rhodium, platinum, and the raw materials of rare metals for secondary battery-manufacturing such as lithium and cobalt. Particularly in 2022, lithium has become the largest share in trade of the raw materials of rare metals in Korea, due to the price surge and increase in demand.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7237-7242
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• 2015

Background: Epithelial ovarian cancer (EOC) is the commonest malignancy involving the ovaries. Maximum surgical cytoreduction (MCR) followed by adjuvant taxane-platinum chemotherapy are the standard of care treatments. Aims: To study treatment outcomes of EOC patients that were maximally cyto-reduced and received adjuvant paclitaxel-carboplatin (PC) chemotherapy. Materials and Methods: This retrospective cohort study included 174 patients with EOC treated at the Egyptian National Cancer Institute between 2006 and 2010. For inclusion, they should have had undergone MCR with no-gross residual followed by adjuvant PC chemotherapy. MCR was total abdominal hysterectomy/bilateral salpingo-oophorectomy [TAH/BSO] or unilateral salpingo-oophorectomy [USO] plus comprehensive staging. Results: The median age was 50 years. Most patients were married (97.1%), had offspring (92.5%), were postmenopausal (53.4%), presented with abdominal/pelvic pain and swelling (93.7%), had tumors involving both ovaries (45.4%) without extra-ovarian extension i.e. stage I (55.2%) of serous histology (79.9%) and grade II (87.4%). TAH/BSO was performed in 97.7% of cases. A total of 1,014 PC chemotherapy cycles were administered and were generally tolerable with 93.7% completing 6 cycles. Alopecia and numbness were the commonest adverse events. The median follow up period was 42 months. The 2-year rates for disease free survival (DFS) and overall survival (OS) were 70.7% and 94.8%, respectively. The respective 5-year rates were 52.6% and 81.3%. Advanced stage and high-grade were significantly associated with poor DFS and OS (p<0.001). Age >65 years was associated with poor OS (p =0.008). Using Cox-regression, stage was independent predictor of poor DFS and OS. Age was an independent predictor of poor OS.

• Journal of Korean Neurosurgical Society
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• v.57 no.3
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• pp.159-166
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• 2015

Objective : We reviewed the feasibility, safety and efficacy as well as the clinical outcome and long-term angiographic results of endovascular treatment (EVT) of the anterior communicating artery (ACoA) aneurysms. Methods : A total of 429 ACoA aneurysms in 426 patients were treated using coil embolization between March 1996 and October 2010 in a single institution. Pretreatment aneurysmal features were checked using angiogram. We had usually used tailored steam shaped microcatheter according to individual angiographic architectures. Immediate postembolization outcomes were evaluated using an angiographic outcome scale and clinical evaluation was performed using the Glasgow Outcome Scale (GOS). Results : Postembolization angiograms demonstrated total occlusion of aneurysm in 290 of 429 (67.6%) aneurysms, neck remnant in 80 (18.6%) and body filling in 59 (13.8%). Dome direction and aneurysm angle was not associated with initial angiographic outcomes. The procedure-related morbidity rate was 0.9% (4 of 429). Clinical and imaging follow-up more than 6 months were available in 382 (89.0%) patients with a mean of 26.2 months. Overall rate of major recanalization was 7.9% (30 of 382) and all of them were retreated without complications. At the last follow-up, 233 (99.2%) of 235 patients had GOS of 5 in unruptured group, and 152 (79.5%) of 191 patients showed good clinical outcomes (GOS of 4 or 5) in ruptured group. Conclusion : Tailored steam shaping of the microcatheter is vital to achieve good angiographic outcomes regardless of aneurysmal direction. EVT is feasible and safe for most ACoA aneurysms with acceptable immediate and long-term outcomes.

• Radiation Oncology Journal
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• v.10 no.1
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• pp.27-34
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• 1992

Cis-Platinum (DDP) was utilized as a radiosensitizer in a pilot study for stage III and IV squamous cell carcinoma between 1984-1987, and DDP 20 $mg/M^2$/day was administered for 4 days at 3 week interval with concurrent radiotherapy. This study consisted of three phases: cytoreduction phase, eradicative treatment phase and adjuvant phase. Total 59 patients were subjected to evaluate a tumor response and its toxicity. During the eradicative phase,27 patients underwent surgery (group I ), 29 patients were treated with radiotherapy only (group II) and 3 patients did not complete the second phase of therapy. At the cytoreduction phase, $95\%$ response rate with complete response (CR) $47.5\%$ and partial response (PR) $47.5\%$ was observed. Complete tumor clearance (CTC) rate following 2nd phase of therapy was $84\%$ (47/56) with 26/27($96\%$) in group I achieved CTC with surgery and 21/29 ($72\%$) patients In group II achieved CTC following 2nd phase. $67\%$ of primary lesions and $70\%$ of nodal diseases in group I showed no tumor in the surgical specimen. $34\%$ of patiets who achieved CTC at 2nd phase developed recurrence and median time to recur was 8 months. Actuarial disease free survival at 4 years was $59\%$ and $51\%$(24/27) of patients who achieved CTC at 2nd phase were alive without any evidence of disease at median follow-up 31 months (range, 10-48 months). There was no significant difference in overall and disease free survival between group I and II between CR and PR group following 1st Phase. Only significant Prognostic factor in this study was the complete tumor clearance following 2nd phase theapy. In general, toxicity was not excessive. Author concludes that this study confirmed the significant radiosensitizing effect of DDP with the acceptable toxicity and warrant the prospective study to determine optimum scheduling for DDP and radiotherapy which maximizes the therapeutic gain.

• Korean Journal of Clinical Pharmacy
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• v.16 no.2
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• pp.131-138
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• 2006

Heptaplatin, a new platinum derivative, has several contradicting reports on the nephrotoxicity. Therefore, the aim of this study is to compare the toxicities of heptaplatin-containing regimens in the chemotherapy. This study was performed retrospectively on seventy-seven patients with advanced gastric cancer who did not receive chemotherapy within the last 1 months before taking of heptaplatin- or cisplatin-containing chemotherapy. The 38 patients among total patients was received heptaplatin-containing regimens (26 with SEF regimens: heptaplatin/epirubicin/5-FU, 12 with SF regimens: heptaplatin/5-FU) and the rest 39 patients was received cisplatin-containg regimens (11 with CEF regimens: cisplatin/epirubicin/5-FU, 28 with ELF regimens: epirubicin/leucovorin/5-FU). Before and after the chemotherapy serum creatinine (Scr) and proteinuria were measured by urine stick test in all patient groups. Also Scr was measured a day before the second cycle and did not vary significantly between groups. However Scr on cycle 3 were significantly higher in SEF and SF groups. In case of proteinuria, it was more frequent on cycle 1 in heptaplatin/5-FU group. Proteinuria before and after on cycle 2 was not different between the two cisplatin -containing groups, but was more frequent in heptaplatin-containing groups. The reason why the Scr measured was not so different could be because we excluded the patients who received only one cycle of heptaplatin and changed the regimen due to signs of nephrotoxcity. As the results nephrotoxicity such as protienuria was appeared to be more frequent with heptaplatin-treated patients. It suggests that the clinical consequences of the toxicity need to further evaluation and also the modalities to prevent or minimize nephrotoxicity of heptaplatin should be studied for future utilization of the drug.

• KSBB Journal
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• v.15 no.4
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• pp.388-392
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• 2000

An on-line glucose flow injection analysis system was developed and used for the automatic analysis and addition of glucose in the cultivationof a Saccharomyces cerevisiae in a korean paper digestion wastewater in order to increase the cell concentration. The system was composed of a ceramic sampler a sampling valve an injection valve an immobilized glucose oxidase column a debbble a flow cell with platinum electrodes a potentiostat a computer and interface system and tubing pumps. The glucose concentration of the wastewater medium was mainitained at the low concentration of $176{\pm}31 mg/L$ with the on-line FIA system and by adding glucose and $>(NH_4)_2S0_4$ the cell concentration as total cell count can be increased by 3.1times.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2369-2373
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• 2015

Objective: To analyze efficacy of neoadjuvant chemotherapy for advanced ovarian cancer. Materials and Methods: A total of 107 patients with advanced ovarian cancer undergoing cytoreductive surgery were divided into a neoadjuvant chemotherapy group (n=61) and a primary debulking group (n=46) and retrospectively analyzed. Platinum-based adjuvant chemotherapy was applied to both groups after cytoreductive surgery ande overall and progression-free survival times were calculated. Results: No significant difference was observed in duration of hospitalization ($20.8{\pm}6.1$ vs. $20.2{\pm}5.4$ days, p>0.05). The operation time of neoadjuvant chemotherapy group was shorter than the initial surgery group ($3.1{\pm}0.7$ vs. $3.4{\pm}0.8$ h, p<0.05). There were no significant differences in median overall survival time between neoadjuvant chemotherapy group and surgery group (42 vs. 55 months, p>0.05). Similarly, there was no difference in median progression-free survival between neoadjuvant chemotherapy group and surgery group (16 vs. 17 months, p>0.05). The surgical residual tumor size demonstrated no significant difference between initial surgery and neoadjuvant chemotherapy groups (p>0.05). Multivariate analysis showed that more than 3 cycles of regimen with neoadjuvant chemotherapy was associated with more resistance to chemotherapy compared with patients without receiving neoadjuvant chemotherapy (OR: 5.962, 95%CI: 1.184-30.030, p<0.05). Conclusions:Neoadjuvant chemotherapy can shorten the operation time. However, it does not improve survival rates of advanced ovarian cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1667-1674
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• 2012

Objective: To explore the differential protein expression profile in EC304 gastric cancer cells induced by alphastatin. Methods: Cultured EC304 cells in the exponential phase of growth were randomly divided into alphastatin and control groups. Total proteins were extracted and the two dimensional electrophoresis (2-DE) technique was applied to analyze differences in expression with ImageMaster 2D Platinum 5.0 software. Proteins were identified using the MASCOT database and selected differently expressed proteins were characterised by western blotting and immunofluorescence. Results: $1350{\pm}90$ protein spots were detected by the ImageMaster software in the 2-DE gel images from the control and alphastatin groups. The match rate was about 72-80% for the spectrum profiles, with 29 significantly different protein spots being identified, 10 upregulated, 16 downregulated, two new and one lost. The MASCOT search scores were 64-666 and the peptide matching numbers were 3-27 with sequence coverage of 8-62%. Twenty-three proteins were checked by mass spectrometry, including decrease in Nm23 and profilin-2 isoform b associated with the regulation of actin multimerisation induced by extracellular signals. Conclusion: The proteome in EC304 cells is dramatically altered by alphastatin, which appears to play an important role in modulating cellular activity and anti-angiogenesis by regulating protein expression and signal transduction pathways through Nm23 and profilin-2 isoform b, providing new research directions for anti-angiogenic therapy of gastric cancer.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.5
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• pp.29-35
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• 1999

Inductively coupled plsama etching of platinum thin film was studied using $O_2$ addition to $Cl_2$/Ar gas plasma. In this study, Pt etching mechanism was investigated with Ar/$Cl_2$ /$O_2$ gas plasma by using XPS and QMS. Ion current density was measured with Ar/$Cl_2$ /$O_2$ gas plasma by using single Langmuir probe. It was confirmed by using QMS and single Langmuir probe that Cl and Ar species rapidly decreased and ion current density was also decreased with increasing $O_2$ gas ratios. These results implied that the decrease of Pt etch rate is due to the decrease of reactive species ans ion current density with increasing $O_2$ gas mixing ratios. A maximum etch rate of 150nm/min and the oxide selectivity of 2.5 were obtained at Ar/$Cl_2$ /$O_2$ flow rate of 50 seem, RF power of 600 W, dc bias voltage of 125 V, and the total pressure of 10 mTorr.

• Korean Journal of Optics and Photonics
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• v.14 no.1
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• pp.38-43
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• 2003

Fabrication process of strain-induced channel waveguides in $LiNbO_3$ was developed using strain-optic effect and compressional strain due to ~1.4 $\mu\textrm{m}$ surface Mo/Pt metal film. Characterization of the channel waveguides revealed a single transverse and depth mode in both TE and TM polarizations. Measurements showed total insertion loss of 6.2 and 7.7 ㏈/cm for TM and TE polarizations. respectively. Electro-optic intensity modulators with 11 mm long electrode length and 21 $\mu\textrm{m}$ electrode gap at $\lambda$ = 1.15 ${\mu}{\textrm}{m}$have been produced in $LiNbO_3$ substrates using strain-induced channel waveguides. Modulation depth of 100% at $\pi$-radian voltage of 16.1V has been demonstrated. Also, 1$\times$2 on/off power splitters at $\lambda$ = 0.63 $\mu\textrm{m}$ have been produced using strain-induced channel waveguides. On/off voltage of $\pm$ 25V has been demonstrated.