• 자원리싸이클링
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• 제5권1호
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• pp.29-33
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• 1996

은을 함유한 폐기물로부터 은을 회수하는 일반적인 공정은 은을 질산으로 용해시킨 후 은이온만을 AgCl로 선택적으로 분리, 적당한 환원제를 사용하여 은을 얻는 방법이다. 본 연구에서는 $Na_2$$CO_3$양이 AgCl의 Ag로의 환원율에 미치는 영향에 대하여 통계학적인 기법(다항다중회귀분석 및 반응표면분석)을 사용하여 검토하였으며 반응시간 1시간, 반응온도 $620^{\circ}C$ 그리고 $Na_2$$CO_3$/AgCl의 당량비가 2.0일 때 96% 이상의 환원율을 얻을 수 있었다.

• Journal of Preventive Medicine and Public Health
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• 제35권2호
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• pp.129-135
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• 2002

목적 : 1998년 한국인 성인에서의 혈청 HBsAg의 양성률을 추정하는 것을 일차적 목적으로 하며, HBsAg 양성률의 연령별로 분포, 지역적 차이, 과거 간질환력, 만성간질환 가족력 및 예방접종과의 관련성을 파악하며 또한 양성자를 6개월간 추적후 재검사 하여 B형 간염의 만성보균율을 파악하고자 하는 것을 이차적 목적으로 하였다. 방법 : 1998년 전국 10개 지역에서 의료보험관리공단의 정기건강검진 수진자를 대상으로 하여 HBsAg의 혈청유병률을 조사하였다. HBsAg 양성인 사람들을 대상으로 6개월 이상 추적조사하여 B형간염 만성보균율을 파악하였다. 총 1,816명에 대한 혈청과 설문서가 수집되었다. HBsAg는 RIA로 측정하였다. 결과 : HBsAg의 혈청유병률은 5.5%(95% CI-4.5-6.6)였으며 남자에서 7.4%(95% CI=5.8-9.4), 여자에서 3.6%(95% CI=2.5-5.0)로 나타났다. 급성간질환 과거력과 만성간질환 가족력을 HBsAg 혈청검사결과와 비교한 결과 유의한 관련성이 있는 것으로 나타났다. HBsAg 양성자에서 6개월 후에 음성으로 전환한 사람은 3.2%(95% CI=0.1-16.7)였으며 따라서 B형간염의 만성보균율은 5.3%(95% CI=3.7-6.6)로 추정되었다. 결론 : 본 연구결과에서는 HBsAg의 양성률이 1980년대의 연구결과들에 비하여 비교적 낮게 추정되었으며 이는 특히 여성과 젊은 연령층에서 두드러지게 나타났다. 그러나 우리나라에서의 간암 및 만성간질환의 공중보건학적 중요성을 고려하면 지속적인 간염발생의 예방대책이 필요하다고 할 수 있다.

• 한국환경보건학회지
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• 제39권4호
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• pp.369-375
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• 2013

Objectives: This study was conducted to identify factors determining the toxicity of manufactured silver nano-particles (AgNPs) on aquatic organisms. Methods: For this purpose, we prepared several AgNPs with varied characteristics, including hydrodynamic size (nano-$^{ABC}Ag^{Cit}\;vs$-sized-$^{ABC}Ag^{Cit}$), impurities ($^{ABC}Ag$ stock vs $^{ABC}Ag$), and citrate capping ($^{ABC}Ag^{Cit}$), using a commercially available manufactured AgNP ($^{ABC}Ag$ stock). Acute tests were conducted using larval zebrafish (Danio rerioI). In addition, in order to determine the ecotoxicological potentials of various capping agents, toxicity tests were conducted with microbes, waterfleas, and fish for eight different capping agents that are used for NPs. Results: The toxicity of AgNPs in terms of 96 h fish $LC_{50}$ increased in the following order: $^{ABC}Ag$ stock < $^{ABC}Ag=^{ABC}Ag^{Cit}=nano-^{ABC}Ag^{Cit}$ < ${\mu}$-sized-$^{ABC}Ag^{Cit}$ < $AgNO_3$. After removing impurities by dialysis, 96 h $LC_{50}$ value decreased significantly from $126.6{\mu}g/L$ (95% confidence intervals [CI]: 107.0-146.2) ($^{ABC}Ag$ stock) to $78.6{\mu}g/L$ (CI: 72.7-84.8) ($^{ABC}Ag$). For ${\mu}$-sized-$^{ABC}Ag^{Cit}$ (ranging between 3.9 and 40.6 nm) and $^{ABC}Ag^{Cit}$ (40.6 nm and $9.1{\mu}m$), the 96 h $LC_{50}$ of the former ($43.9{\mu}g/L$, CI: 36.0-51.7) was approximately two-fold lower than that of the latter ($87.0{\mu}g/L$, CI: 73.5-100.3). Conclusions: In this study, we found that for acute lethality, the contribution of impurities and particle size was significant, but that of citrate was negligible.

• Journal of Preventive Medicine and Public Health
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• 제30권1호
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• pp.1-15
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• 1997

To investigate the association between hepatocellular carcinema(HCC) and infection of hepatitis B virus(HBV) and hepatitis C virus(HCV) in an HBV endemic area, a case-control study of 254 patients with HCC and of 1,270 age and sex matched health control subjects was done. Among the 254 HCC patients 166(65.4%) were positive for hepatitis B surface antigen(HBsAg), 49(19.3%) were positive for HCV antibody (anti-HCV Ab). The crude odd ratio of patients with HBsAg was 36.1(95% CI :22.4-58.2) and with anti-HCV Ab was 9.0(95% CI :5.5-14.6). In an analysis, which HBsAg(-), HBcAb(-), anti-HCV Ab(-) group was chosen as referent group, odd ratio of HBsAg(+) group was 14.4(95% CI: 7.2-28.9) and of anti- HCV Ab(+) was 10.7(95% CI: 2.9-40.0). odd ratio of anti-HCV Ab(+), HBsAg(+) group and anti-HCV Ab(+), HBsAg(-), HbcAb(+) group for HCC were elevated to 27.3(95% CI : 9.0-82.9), 15.9(95% CI:7.1-35.8) respectly, The odd ratio of anti-HCV Ab(-), HBsAg(-), HBcAb(+) group was 2.4(95% CI : 1.1-5.0). These result suggested that HBV and HCV were associated with HCC. In HBV endemic area patients with HBcAb alone should be considered risk group for HCC.

• 한국분말재료학회지
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• 제11권6호
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• pp.477-485
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• 2004

Monodispersed flaky silver powder was obtained by controlling the ratios of $H_{2}O_{2}/NH_{3}$ and Agin in a mixed solution of ethylene glycol and ammonia with an addition of PVP. The effects of $NH_{3}/Ag,\; H_{2}O_{2}/Ag\;and\;H_{2}PtCl_{6}/Ag$ on its morphology and size were investigated. In $H_{2}O_{2}-NH_{3}-AgNO_{3}\;system,\;NH_{3}/Ag$ molar ratio was found to be an important reaction factor for the nucleation and crystal growth of Ag powder. The synthesis of flaky powder was optimized at over 6 of $NH_{3}/Ag \;and\;5\;of\;H_{2}O_{2}/Ag\;under\;1.0{\times}10^{-3}\;of\;Pt/Ag.\;Moreover,\;as\;the\; NH_{3}/Ag$ molar ratio increased, the size of precipitates was increased regardless of the amount of Pt. In the absence of $H_{2}PtCI$, the morphology and size of reduced Ag powder were found to be irregular in shape $2-4{\mu}m$ in diameter. However, homogenized fine Ag powder was obtained due to heterogeneous nucleation when $H_{2}PtCI$ used as a cat-alyst, and flaky one was synthesized with the addition of Pt over $1.0{\times}10^{-3}$ of Pt/Ag.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6207-6210
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• 2012

Introduction: Although a number of studies were published in the past several years on associations between hsa-mir-27a and cancer risk, the findings remain conflicting rather than conclusive. To derive a more precise effect on the association between SNP hsa-mir-27a rs895819 and breast cancer risk, we conducted a meta-analysis for the first time. Materials and Methods: Through retrieval from PubMed for the period up to August 2012, a total of four studies were identified with 3,287 cases and 4,298 controls for SNP hsa-mir-27a rs895819. We calculated summary odds ratio (ORs) and corresponding 95% confidence intervals (CIs) using a fixed effects model (when the heterogeneity was absent, P>0.10). Otherwise, the random-effects model was used. Results: We found that hsa-mir-27a rs895819 polymorphism also did not reveal any relationship with breast cancer susceptibility (AG versus AA: OR = 0.98; 95%CI, 0.73-1.32; GG versus AA: OR = 0.86; 95% CI, 0.72-1.03; AG/GG versus AA: OR = 0.92; 95% CI, 0.74-1.14), while significantly decreased risk was found among Europeans in AG versus AA and AG/GG versus AA models tested (AG versus AA: OR = 0.83; 95%CI, 0.72-0.97; GG versus AA: OR = 0.86; 95% CI, 0.71-1.05; AG/GG versus AA: OR = 0.84; 95% CI, 0.75-0.94). Conclusion: These findings suggest that hsa-mir-27a rs895819 polymorphism may play an important role in breast cancer development.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2517-2522
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• 2014

Background: Several recent studies have explored associations between pre-mir-218 polymorphism (rs11134527) and cancer risk. However, published data are still inconclusive. To obtain a more precise estimation of the relationship in the Chinese population, we carried out a meta-analysis for the first time. Materials and Methods: Through retrieval from the PubMed, Medline, Embase, Web of Science databases, China National Knowledge Infrastructure and the Chinese BioMedical Literature Database, a total of four studies were analyzed with 3,561 cases and 3,628 controls for SNP pre-mir-218 rs11134527. We calculated odds ratios (ORs) and 95% confidence intervals (95%CIs) to explore the strength of associations. Results: The results showed that the rs11134527 polymorphism was associated with decreased cancer risk in GG versus AA and GG versus AA+AG models tested ( GG vs AA: OR=0.82, 95%CI: 0.71-0.94; GG vs AA+AG: OR=0.84, 95%CI: 0.74-0.96), and significantly decreased cervical cancer risk was observed in GG versus AA and GG versus AA+AG models (GG vs AA: OR=0.79, 95%CI: 0.66-0.94; GG vs AA+AG: OR=0.80, 95%CI: 0.68-0.94). However, no significant association between the rs11134527polymorphism and hepatocellular carcinoma risk was observed in all comparison models tested (AG vs AA: OR=0.94, 95%CI: 0.79-1.11; GG vs AA: OR=0.88, 95%CI: 0.70-1.10; GG+AG vs AA: OR=0.92, 95%CI: 0.79-1.08; GG vs AA+AG: OR=0.91, 95%CI: 0.75-1.11). Conclusion: The findings suggest that pre-miR-218 rs11134527 polymorphism may have some relation to cancer development in Chinese. However, well-designed studies with larger sample size and more detailed data are needed to confirm these conclusions.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6855-6861
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• 2014

Background: Previous epidemiological studies have suggested a potential role of the $HSPA1B{\pm}1267A/G$ polymorphism in risk of developing cancer. However, the results were inconsistent. Therefore, we performed this meta-analysis to summarize the possible association with cancer risk. Materials and Methods: We retrieved relevant articles from PubMed, EMBASE, ISI Web of Science, Chinese Biomedical Literature and Chinese National Knowledge Infrastructure. Studies were selected using specific criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess those associations. All analyses were performed using STATA software. Results: Fourteen case-control studies, including 1, 834 cancer cases and 2, 028 controls were included in this meta-analysis. Overall, the results indicated that the G allele of HSPA1B gene ${\pm}1267A/G$ was significantly associated with an increased cancer risk in all genetic models (G vs A: OR=1.51, 95%CI 1.17-1.95, p=0.001; GG vs AA: OR=2.93, 95%CI 1.50-5.74, p=0.002; AG vs AA: OR=1.48, 95%CI 1.10-1.98, p=0.009; GG/AG vs AA: OR=1.69, 95%CI 1.22-2.33, p=0.001; GG vs AG/AA: OR=2.31, 95%CI 1.24-4.32, p=0.009). In the subgroup analysis stratified by ethnicity, a significant association was identified in Caucasians (G vs A: OR=1.35, 95%CI 1.08-1.69, p=0.008; GG/AG vs AA: OR=1.36, 95%CI 1.09-1.70, p=0.007), but not in Asians. In the stratified analysis by cancer types, individuals with the G allele showed an increased risk of hepatocellular carcinoma compared with carriers of the A allele (OR=2.40, 95%CI 1.47-3.91, p<0.001). Inversely, individuals with the GG genotype showed a decreased risk of gastric cancer compared with carriers of the AG/GG genotypes (GG vs AG/AA: OR=0.39, 95%CI 0.20-0.70, p=0.007). Conclusions: This meta-analysis suggests associations between the HSPA1B ${\pm}1267A/G$ polymorphism and risk of cancer. However, this association might be Caucasian-specific and the G allele of this polymorphism probably increases risk of hepatocellular carcinoma while decreasing risk of gastric cancer. Further well-designed studies based on larger sample sizes are needed to validate these findings.

• Archives of Pharmacal Research
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• 제21권5호
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• pp.521-526
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• 1998

The physicochmical properties of recombinant hepatitis B surface antigen (r-HBsAg), which was expressed in C127 mammalian cell were studied. Using roller bottle culture in DMEM supplemented with fetal bovine serum, 10-15 mg/L of r-HBsAg was produced with about 31% of purification yield. The purity of r-HBsAg by HPLC was 99.8% and electron microscopic examination showed homogeneous spherical particle with 22 nm in diameter, a morphological characteristic of HBsAg. The density of r-HBsAg by CsCI density gradient method was 1.19g/ml and the isoelectric point by Mono $P^{TM}$ HR 5/20 column was 4.6. The analysis of subunit protein pattern using SDS-PAGE followed by scanning densitometry gave 81.3% of S protein and 18.7% of pre-S protein. fluorophore-assisted-carbohydrate-electrophoresis analysis showed the relative amount of carbohydrate to protein was 1.7% and it smajr component was N-acetyl glucosamine, which was about 39% of total carbohydrate. The relative amount of lipid to protein determined by vanillin phosphoric acid method was 32.5% and its major component was phospholipid, which was about 70% of total lipid. The physicochemical properties of C127 mammalian cell-derved r-HBsAg are similar to those of p-HBsAg, suggesting that the r-HBsAg can be used in developing a new preventive vaccine against hepatitis B.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3273-3278
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• 2014

Background: Various studies have evaluated the relationship between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and hepatocellular carcinoma (HCC) risk, but the conclusions have been inconsistent and underpowered. The purpose of this updated meta-analysis was to examine whether XRCC1 Arg399Gln polymorphism confers susceptibility to HCC. Methods: Eligible studies extracted from PubMed, Embase, Cochrane Library, VIP (chinese) and CNKI (chinese) up to November 2013 were included in the study. Pooled odds ratio (OR) together with their 95% confidence interval (CI) were estimated to evaluate XRCC1 Arg399Gln polymorphism and HCC risk. Results: Finally, 21 studies with 4,170 cases and 5,030 controls were involved in our meta-analysis. The results demonstrated that there was significant association between Arg399Gln polymorphism and HCC risk under two contrast models in overall populations (AG vs GG: OR=1.265, 95%CI=1.036-1.545, p=0.021; AA+AG vs GG: OR=1.240, 95%CI=1.021-1.506, p=0.030). In subgroup analyses, significant association was found in Asians (A vs G: OR=1.175, 95%CI=1.013-1.362, p=0.033; AG vs GG: OR=1.317, 95%CI=1.070-1.622, p=0.009; AA+AG vs GG: OR=1.289, 95%CI=1.055-1.575, p=0.013) and Caucasians (A vs G: OR=0.591, 95%CI=0.361-0.966, p=0.036; AA+AG vs GG: OR=0.468, 95%CI=0.234-0.934, p=0.031). Conclusions: The results suggest that XRCC1 Arg399Gln polymorphism may increase HCC risk especially among Asians. However, XRCC1 Arg399Gln polymorphism might act as a protective role against HCC among Caucasians.