• Advances in environmental research
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• 제7권3호
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• pp.225-237
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• 2018

The sorption of metal ions with low-cost adsorbents plays an important role in sustainable development. In the present study, the efficacy of sugarcane bagasse, rain tree fruits (samaneasaman), banana stem and their mixtures, used as bio-sorbents, in the removal of Cu(II) and Pb(II) ions from aqueous solution is evaluated. Batch studies are conducted, and residual ions were measured using Inductively Coupled Plasma (ICP)-atomic spectrometer. Effect of pH, initial metal ion concentration, reaction time and adsorbent dosage are studied. The Pb(II) removal efficiency was observed to be 97.88%, 98.60% and 91.74% for rain tree fruits, banana stem and a mixture of adsorbents respectively. The highest Cu(II) ion removal was observed for sugarcane bagasse sorbent with an efficiency of 82.10% with a pH of 4.5 and a reaction time of 90 min. Finally, desorption studies were carried out to study the leaching potential of adsorbent, and it was found that the adsorbent is stable in water than the other leaching agents such as HCl, ammonium acetate, Sodium EDTA. Hence, these adsorbents can be effectively used for the removal of these heavy metals.

• 동아시아식생활학회지
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• 제11권4호
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• pp.259-267
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• 2001

납중독에 따른 식이내 Se 함량이 간조직의 산화적 손상을 방어할 수 있는 가를 관찰하기 위해 140g 내외의 흰쥐 Sprague-Dawley종 수컷을 정상군과 식이 내에 납 함량을 2,000 ppm 투여한 납투여 실험군으로 나누고 다시 식이내 Se 수준에 따라 0 ppm(Pb0군), 0.5 ppm(PbS군), 1.0 ppm(PbSS군) 식이군으로 나누어 4주간 사육한 후 간장 중 SOD. GSH-Px, GST 등 항산화효소의 활성을 측정하고, GSH 및 비타민 E 함량을 측정하였다. 또한 전자현미경을 통하여 간세포의 소기관을 관찰하였다. 1. 간장 중 SOD는 Pb0군이 다른 군에 비해 다소 높았다. GSH-Px 활성은 Pb0군은 정상군에 비해 현저하게 감소되었으나 PbS군과 PbSS군간은 Pb0군에 비해 증가되었다. GST활성은 Pb0군만 정상군에 비해 감소되었고 PbS, PbSS,군은 정상군 수준이었다. 2. GSH 함량은 정상군에 비해 Pb0군에서 낮았으나 정상군과 PbS. PbSS군은 유의적인 차이가 없었다. GSSG는 GSH와 반대로 Pb0군에서 증가되었으며 GSH/GSSG는 GSH함량과 같은 경향이었다. 또한 간조직 중의 비타민 E함량은 Pb0군은 정상군에 비해 약 50% 정도의 수준이었고 PbSS군과 PbS군은 Pb0군에 비해 증가되었다. 3. 전자현미경적 관찰에서는 RER의 감소, 라이소솜의 증가, 미토콘드리아의 종창 등을 나타내었는데 그 정도는 PbSS, PbS, Pb0군 순으로 심하게 나타났다. 이상의 결과로 식이 중 Se의 다량 첨가는 납중독으로 인한 간조직의 항산화계를 강화시키고 세포 소기관들의 산화적 손상을 현저하게 완화시킬 수 있음을 알 수 있다.

• 한국세라믹학회지
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• 제29권3호
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• pp.211-215
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• 1992

Crack free PbTiO3 ceramics were produced by sol-gel processing using alkoxide, which has not been reported to be successful. The PbTiO3 gels were prepared from Ti alkoxide and lead acetate without any dopants. They were calcined at $600^{\circ}C$ and miled to produce fine PbTiO3 powder. It was pressed into discs and they were sintered at 110$0^{\circ}C$ for a few hours. The sintered ceramics were relativley hard and dense as having about 96% of theoretical density of PbTiO3. Fabrication of pure PbTiO3 ceramics by sol-gel processing is possibly due to their small grain size and uniform distribution of residual stress created during cubic-tetragonal transition over large number of small grains in fine grain PbTiO3 ceramics.

• Archives of Pharmacal Research
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• 제28권9호
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• pp.1031-1036
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• 2005

[ $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ ] (1) was isolated from an ethyl acetate extract of the root bark from Lycium chinense Miller, and its structure was determined using 1D and 2D NMR spectroscopy including DEPT, HMQC, and HMBC. $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ exhibited potent antimicrobial activity against antibiotic-resistant bacterial strains, methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients, and human pathogenic fungi without having any hemolytic effect on human erythrocytes. In particular, compound 1 induced the accumulation of intracellular trehalose on C. albicans as stress response to the drug, and disrupted the dimorphic transition that forms pseudo-hyphae caused by the pathogenesis. This indicates that $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ has excellent potential as a lead compound for the development of antibiotic agents.

• Applied Microscopy
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• 제1권1호
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• pp.27-34
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• 1969

The compound eyes of the adult Drosophila melanogaster were. fixed in 1.25 per cent glutaraldehyde and 1 per cent osmium tetroxide buffered with sodium cacodylate at pH 7.2. Double fixed specimens were dehydrated using the alcohol series and embedded in Epon 812. They were sectioned with porter blum and JUM 5B ultra-microtome and then stained with lead hydrooxide and uranyl acetate. All thin sections were examined with Hitachi HS-7 or HU-11 electron microscope. The rhabdomere of the compound eye is composed of numerous microvilli packed, arranged, and projected from inner edge of each retinal cell. Each microvillus consisted of a centrum, about $82{\AA}$ in diameter, surrounded by the substances, about $105{\AA}$ in width, which were bounded with double membrane about $44{\AA}$ in thickness. In each inner edge of the microvilli, there was a cylinder, about $175{\AA}$ in diameter, in parallel with retinal cells, which contained a cylindrical axis about $583{\AA}$ in diameter. The surface of the outer edges .of .the microvilli was bounded with reticullar substances about $500{\AA}$ in thickness.

• 한국결정학회지
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• 제7권2호
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• pp.133-146
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• 1996

전기 도금법으로 제조한 백금흑의 형상과 적외선 흡수특성을 XRD, SEM, IR 분광기를 사용하여 조사하였다. 금(Au)이 입혀진 알루미나 유리기판 위에 pH 1.0∼1.5에서 1∼5분동안 백금층을 입혔는데, 염화백금과 아세트산 납으로 제조한 용액을 전해액으로 사용하였다. 전류밀도가 20∼50 mA/㎠일 때 백금흑은 수지상으로 성장하여 "나무"와 같은 형태를 보였다. 백금흑의 면적밀도가 1.3mg/㎠ 이상일 때 10μm의 적외선에서 측정한 수광효율은 90% 이상이었다.

• 한국식품영양과학회지
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• 제19권3호
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• pp.224-228
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• 1990

Cabbage contained high peroxidase activity among tested plant sources. The cabbage peroxi-dase can replace horseradish peroxidase to assay glucose with glucose oxidase. The amount of glucose can be determined quantitatively by glucose oxidase-cabbage peroxidase. The opti-mum pH and temperature for enzymatic glucose determination by glucose oxidase-cabbage peroxidase were 6.0 and 35-45$^{\circ}C$ respectively. The glucose assay was inhibited by addition of various metal salts such as mercuric chloride lead acetate silver nitrate ammonium molyb-date sodium tunstate and cupric sulfate. The relationship between absorbance and amount of glucose was linear up to 8.33 mM glucose in the assay mixture under the assay conditions.

• Applied Microscopy
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• 제50권
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• pp.14.1-14.6
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• 2020

Scanning electron microscopy (SEM) plays a central role in analyzing structures by imaging a large area of brain tissue at nanometer scales. A vast amount of data in the large area are required to study structural changes of cellular organelles in a specific cell, such as neurons, astrocytes, oligodendrocytes, and microglia among brain tissue, at sufficient resolution. Array tomography is a useful method for large-area imaging, and the osmium-thiocarbohydrazide-osmium (OTO) and ferrocyanide-reduced osmium methods are commonly used to enhance membrane contrast. Because many samples prepared using the conventional technique without en bloc staining are considered inadequate for array tomography, we suggested an alternative technique using post-staining conventional samples and compared the advantages.

• Natural Product Sciences
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• 제3권1호
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• pp.19-28
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• 1997

Constitutive cyclooxygenase (COX-I) is present in cells under physiological conditions, whereas inducible cyclooxygenase (COX-II) is induced by some cytokines, mitogens, and endotoxin presumably in pathological conditions such as inflammation. We have evaluated the inhibitory effects of solvent fractionated extracts of natural products on the activities of COX-I and COX-II. Oxygen uptake COX assay was performed, as a primary screening from the tissue extracts of bovine seminal vesicles (BSV), by monitoring the initial rate of oxygen uptake using an oxygen electrode. Additionally, we evaluated plant extracts for the inhibitory effects of COX-I (in HEL cells) and COX-II (in lipopolysaccharide activated J774A.1 macrophages) using thin layer chromatography of prostanoids produced from $^{14}C-labelled$ arachidonic acid (AA). The use of such models of COX-I and COX-II assay will lead to the identification of specific inhibitors of cyclooxygenases with presumably less side effects than present therapies. Inhibitory effects of 50 kinds of plant extracts on the COX-I and COX-II activities were determined and the active fractions were found in the ethyl acetate fractions of Dryopteris crassirhizoma (roots), Amomum cardamomum (roots), Triticum aestivum (seeds), Perilla sikokiana (leaves), Anemarrhena asphodeloides (roots). Especially, the ethyl acetate fraction of Dryopteris crassirhizoma (roots), which exhibited the strong inhibition against BSV COX $(IC_{50},\;65.4\;{\mu}g/ml)$, COX-I $(IC_{50},\;8.5\;{\mu}g/ml)$, and COX-II $(IC_{50},\;17.2\;{\mu}g/ml)$, is under investigation to isolate active principles using activity-guided fractionation method.

• Applied Microscopy
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• 제22권2호
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• pp.118-126
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• 1992

The pathway and time course of fucose-containing glycoprotein synthesis and intracellular translocation in osteoclasts of the mice maxillary alveolar bone were investigated by electron microscopic radioautography. Male Balb-C mice weighing 17gm were anesthetized with Nembutal and injected via the external jugular vein with 2.5 mCi of $L-[6-^{3}H]-fucose$ (specific activity 16.8 mCi/mmol) in 0.1 ml of sterile saline solution. At 5, 10, 20, 35 minutes and 8 hours after administration of the $^{3}H-fucose$, animals were killed by intracardiac perfusion of 30ml of 2% glutaraldehyde in a modified Tyroid solution, pH 7.4. The maxillae were then removed and further fixed in Karnovsky fixative for an additional 3-4 hours. After rinsing in 0.1M cacodylate buffer for 10 minutes, the maxillae were demineralized for 2 weeks at $4^{\circ}C$ in ethylene diamine tetra acetate containing 2% glutaraldehyde. The first interdental areas were mesiodistally sectioned into slices of 1mm thickness and postfixed in osmium tetroxide. Tissues were then dehydrated and embedded in Poly Bed. To prepare electron microscopic radioautography, the dipping method of Kopriwa (1973) was employed. Thin sections were coated with a crystalline monolayer of ILford $L_4$ photographic emulsion. After exposure for 4 months at $4^{\circ}C$, the sections were developed Kodak Microdol-X and Phenidon (for compact grains), fixed in 30% sodium thiosulfate, stained with uranyl acetate and lead citrate and examined in the electron microscope (JEOL 1200 EX). At 5, 10 and 20 minutes after injection, $^{3}H-fucose$ was concentrated in Golgi cisternae of the osteoblasts. By 35 minutes the labels were observed over small vesicles in the suprannclear area of osteoclasts. At 8 hours, numerous silver grains were located on the ruffled border and cell membrane of osteoclasts. These results indicate that fucose molecules are added in the Golgi apparatus and small vesicles appear to be responsible for translocation of the glycoproteins to the marginal portion of osteoblasts. The glycoproteins are distributed on the osteoclast cell surface and especially over the ruffled border.