• Journal of Ecology and Environment
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• 제43권1호
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• pp.22-30
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• 2019

Background: Piton du Milieu (PdM) impounding reservoir is suspected to be eutrophic based on the elevated level of orthophosphate and nitrate. Water supplies from three adjacent rivers are primarily thought to contribute to the nutrient enrichment of the reservoir. It is also suspected that there is leaching of orthophosphate, nitrate and organic matter into the rivers during rainfall events and also as a result of anthropogenic activities within the catchment area. The aim of this study was to ascertain the impact of nutrient loading on the water quality of PdM water and on the population of freshwater microalgae in the reservoir. The enumeration and identification of algae from PdM were performed by differential interference contrast microscopy. Dissolved oxygen (DO) and pH were determined by electrometric methods, whereas nutrient levels, silica and total organic carbon (TOC) were determined by instrumentation techniques. Results: Annual mean orthophosphate, nitrate and total organic carbon input from the three feeders within the catchment area of PdM reached levels as high as 0.09 mg/L, 0.4 mg/L and 2.62 ppm respectively. Over a 12-month period, mean TOC concentration in the reservoir was 2.32 ppm while the mean algal cell count was 4601 cells/mL. The dominant algal species identified were Oscillatoria, Cyclotella, Navicula and Cosmarium. Conclusion: This study highlights the trophic state of the reservoir water and clearly points to the need for constant monitoring in order to avoid the occurrence of an impending harmful algal bloom.

• 자원리싸이클링
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• 제23권6호
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• pp.22-29
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• 2014

네오디뮴 폐자석 침출액으로부터 희유금속인 네오디뮴을 회수하는 연구와 함께 네오디뮴과 같이 침출되는 철의 부가가치를 높이는 연구가 필요하다. 본 연구에서는 네오디뮴과 같이 침출되는 철의 유용자원화를 위한 기초연구로 철 나노분말을 제조하는 실험을 수행하였다. 본 연구는 $FeCl_3$ 용액을 철 분말 원료로, 분산제는 $Na_4P_2O_7$와 Polyvinylpyrrolidone를 이용하였고, 환원제로는 $NaBH_4$, 철 나노분말 핵생성 촉진제 seed로 염화팔라듐을 사용하였다. 제조한 철 나노분말을 XRD, SEM을 이용하여 분말의 형상 및 크기를 분석하였다. Fe와 $NaBH_4$의 몰 비를 1 : 5로 조절하여 철 분말을 제조하였으며, 이 때 철 분말은 구형이었으며, 입도는 약 50 ~ 100 nm 였다. 분산제 $Na_4P_2O_7$의 경우 100 mg/L에서 철 이온의 제타포텐셜이 음의 값을 가졌고, $FeCl_3$ 과 PVP와 Pd의 질량비 1 : 4 : 0.001에서 분산이 양호하고, 입도가 100 nm 인 철 나노분말을 합성하였다. 같은 반응 조건에서 폐 Nd 침출액의 Fe 이온을 pH를 조절하여 슬러리화한 후 실험을 진행한 결과, pH 9에서 구형의 철 분말을 합성할 수 있었으며, 20 L 이상의 Scale-up 공정에서는 분산제 없이 환원제로 175 nm 크기의 철 분말을 합성할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제36권6호
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• pp.377-383
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• 2006

The purpose of the present study was to examine the pharmacokinetic characteristics of arsenic hexaoxide($As_4O_6$), a novel anticancer compound, after i.v. bolus and oral administration in rats. We developed an ICP-Mass based method to analyze arsenic hexaoxide levels in plasma, bile, urine, feces, and tissue and validated the method. Arsenic hexaoxide rapidly disappeared from the plasma by 10 min($\alpha$ phase) after i.v. administration, which was followed by the late disappearance in the $\beta$ phase. The mean plasma half-lives($t_{1/2}$) of arsenic hexaoxide at the a and $\beta$ phase when administered at a dose of 5 mg/kg were 1.57 and 29.8 min, respectively. The maximum plasma concentration($C_{max}$) was 230 ng/mL, after oral administration of arsenic hexaoxide at a dose of 50 mg/kg. The bioavailability, which was calculated from the dose-adjusted ratio, of the oral administered arsenic hexaoxide was 1.61%. Of the various tissues tested, arsenic hexaoxide was mainly distributed in the spleen, lung, liver and kidney after oral administration. Arsenic hexaoxide levels in the spleen or lung at 24 hr after oral administration were higher than those of maximum plasma concentration($C_{max}$). The cumulative amounts of arsenic hexaoxide found in the urine by 48 hr after the administration of 50 mg/kg were 5-fold higher than those in the bile. However, the cumulative amounts in the feces were 10-fold higher compared with those of urine, suggesting that arsenic hexaoxide is mostly excreted in the feces. In conclusion, our observations indicated that arsenic hexaoxide was poorly absorbed from the gastro-intestinal tract to the blood circulation and transferred to tissues such as the spleen and lung at 24 hr after oral administration. Moreover, the majority of arsenic hexaoxide appears to be excreted in the feces by 48 hr after oral administration.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2008년도 제35회 하계학술대회 초록집
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• pp.97-97
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• 2008

• Journal of Yeungnam Medical Science
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• 제38권4호
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• pp.308-317
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• 2021

Cancer is the leading cause of death and is on the rise worldwide. Until 2010, the development of targeted treatment was mainly focused on the growth mechanisms of cancer. Since then, drugs with mechanisms related to tumor immunity, especially immune checkpoint inhibitors, have proven effective, and most pharmaceutical companies are striving to develop related drugs. Programmed cell death-1 and programmed cell death ligand-1 inhibitors have shown great success in various cancer types. They showed durable and sustainable responses and were approved by the U.S. Food and Drug Administration. However, the response to inhibitors showed low percentages of cancer patients; 15% to 20%. Therefore, combination strategies with immunotherapy and conventional treatments were used to overcome the low response rate. Studies on combination therapy have typically reported improvements in the response rate and efficacy in several cancers, including non-small cell lung cancer, small cell lung cancer, breast cancer, and urogenital cancers. The combination of chemotherapy or targeted agents with immunotherapy is one of the leading pathways for cancer treatment.

• Journal of Pharmaceutical Investigation
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• 제38권3호
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• pp.191-197
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• 2008

The purpose of the present study was to examine the pharmacokinetics and lymphatic delivery of the oligopeptide, a model peptide of X antigen epitope peptides, after the intramuscular administration of the peptide-bearing liposomes in rats. $^{14}C$-labelled peptide was used as a tracer to analyze the peptide levels in plasma, bile, urine, tissue homogenates, and lymph nodes (superior cervical nodes, brachial nodes and superior mesenteric nodes). Model peptide rapidly disappeared from the plasma by 30 min (${\alpha}$ phase) after i.v. administration, which was followed by the late disappearance. The apparent plasma half-lives ($t_{1/2({\alpha}),app}$) of the peptide at the ${\alpha}$ phase when administered at a dose of 0.2-1.0 mg/kg were about 5 min. The maximum plasma concentration ($C_{max}$) was $1.52\;{\mu}g/mL$, after the i.m. administration of the peptide at a dose of 1.0 mg/kg. The bioavailability, which was calculated from the time zero to last quantitative time, of the i.m. administered peptide was over 60%. Of the various tissues tested, the peptide was mainly distributed in the kidney after the i.m. administration. The peptide levels in the kidney 3 hr after the i.m. administration were higher than those of maximum plasma concentration ($C_{max}$). The cumulative amounts of the peptide found in the urine 72 hr after the administration of 1.0 mg/kg were 2-folder higher than those in the bile, suggesting that the peptide is mostly excreted in the urine. Moreover, the concentrations of the peptide in the lymph nodes were as high as that of the plasma and the tissues. In conclusion, the peptide concentration in the lymph nodes was maintained by 24 hr after the i.m. administration of the peptide-bearing liposomes.

• 대한화장품학회지
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• 제19권1호
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• pp.20-30
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• 1993

본 연구는 역상 HPLC를 이용하여 Pb(IEAA-NR)2 (R=H, CH3, C3H7, C6H5, C4H9) 킬레이트를 동시 분리하기 위한 최적 분리 조건을 조사하고 이들의 용리거동에 관련된 인자들과의 관계를 검토하였는데 그 결과는 다음과 같다. 1. 각 Pb(IEAA-NR)2 킬레이트의 분리에 대한 기기의 최적 조건을 실험적으로 측정한 결과는 다음과 같다. 분리관 : Micropak MCH-5 (4.0 mm I.D. $\times$ 15 cm L, Particle size 5 $\mu\textrm{m}$) 용리액 : MeOH / H20 (73/27) 흐름속도 : 0.7 ${\mu}\ell$/min. 시료주입량 : 4 ${\mu}\ell$ 검출기 : UV 검출기 (254 nm) 2. 용리액의 흐름속도는 0.7${\mu}\ell$/min. 일때 적당한 분리 시간과 좋은 분리도를 나타내었다. 3. 시료 용매가 킬레이트의 머무름 시간에는 큰 영향을 주지 않았으며 금속 킬레이트간의 겸침 현상이 줄어들고 봉우리 면적이 큰 CH3CN을 사용하였다. 4. 용리액의 조성은 MeOH/H2O 의 비가 73/27 으로써 대개의 경우에 lig k' 값이 0$\leq$log k' $\leq$1을 잘 만족하지 않았으며 전체적으로 적당한 분리시간과 좋은 분리도를 나타내었다. 5. Pb(IEAA-NR)2 킬레이트의 log k' 값을 이성분 용매계에서 물의 부피 분율에 대하여 plot한 결과 이들이 직선적인 관계를 가지는 것으로 보아 Pb(IEAA-NR)2 의 머무름은 소수성 효과(Hydrophobic effect)에 크게 기인 한다는 것을 알 수 있었다.

• Radiation Oncology Journal
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• 제34권4호
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• pp.250-259
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• 2016

Immune checkpoint blockades including monoclonal antibodies (mAbs) of cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) have been emerged as a promising anticancer therapy. Several immune checkpoint blockades have been approved by US Food and Drug Administration (FDA), and have shown notable success in clinical trials for patients with advanced melanoma and non-small cell lung cancer. Radiotherapy is a promising combination partner of immune checkpoint blockades due to its potent pro-immune effect. This review will cover the current issue and the future perspectives for combined with radiotherapy and immune checkpoint blockades based upon the available preclinical and clinical data.

• IMMUNE NETWORK
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• 제20권1호
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• pp.10.1-10.14
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• 2020

Immune checkpoint inhibitors (ICIs) have shown remarkable benefit in the treatment of patients with non-small-cell lung cancer (NSCLC) and have emerged as an effective treatment option even in the first-line setting. ICIs can block inhibitory pathways that restrain the immune response against cancer, restoring and sustaining antitumor immunity. Currently, there are 4 PD-1/PD-L1 blocking agents available in clinics, and immunotherapy-based regimen alone or in combination with chemotherapy is now preferred option. Combination trials assessing combination of ICIs with chemotherapy, targeted therapy and other immunotherapy are ongoing. Controversies remain regarding the use of ICIs in targetable oncogene-addicted subpopulations, but their initial treatment recommendations remained unchanged, with specific tyrosine kinase inhibitors as the choice. For the majority of patients without targetable driver oncogenes, deciding between therapeutic options can be difficult due to lack of direct cross-comparison studies. There are continuous efforts to find predictive biomarkers to find those who respond better to ICIs. PD-L1 protein expressions by immunohistochemistry and tumor mutational burden have emerged as most well-validated biomarkers in multiple clinical trials. However, there still is a need to improve patient selection, and to establish the most effective concurrent or sequential combination therapies in different NSCLC clinical settings. In this review, we will introduce currently used ICIs in NSCLC and analyze most recent trials, and finally discuss how, when and for whom ICIs can be used to provide promising avenues for lung cancer treatment.

• Biomolecules & Therapeutics
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• 제19권1호
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• pp.118-125
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• 2011

Free radical scavenging and antioxidants have attracted attention as a way to prevent the progression of Parkinson's disease (PD). This study was carried out to investigate the effects of n-hexane fraction from Laurus nobilis L. (Lauraceae) leaves (HFL) on dopamine (DA)-induced intracellular reactive oxygen species (ROS) production and apoptosis in human neuroblastoma SH-SY5Y cells. Compared with apomorphine (APO, $IC_{50}=18.1\;{\mu}M$) as a positive control, the HFL $IC_{50}$ value for DA-induced apoptosis was $3.0\;{\mu}g/ml$, and two major compounds from HFL, costunolide and dehydrocostus lactone, were $7.3\;{\mu}M$ and $3.6\;{\mu}M$, respectively. HFL and these major compounds significantly inhibited ROS generation in DA-induced SH-SY5Y cells. A rodent 6-hydroxydopamine (6-OHDA) model of PD was employed to investigate the potential neuroprotective effects of HFL in vivo. 6-OHDA was injected into the substantia nigra of young adult rats and an immunohistochemical analysis was conducted to quantitate the tyrosine hydroxylase (TH)-positive neurons. HFL significantly inhibited 6-OHDA-induced TH-positive cell loss in the substantia nigra and also reduced DA induced $\alpha$-synuclein (SYN) formation in SH-SY5Y cells. These results indicate that HFL may have neuroprotective effects against DA-induced in vitro and in vivo models of PD.