• Preventive Nutrition and Food Science
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• v.6 no.3
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• pp.176-179
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• 2001

The present study was designed to investigate the hypoglycemic activity and lipid metabolism of ethanol (EtOH) extract from the aleurone layer of anthocyanin-pigmented (AP) rice in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats weighing 210~240 g were divided into 4 groups, normal, diabetic control, and two experimental groups, and diabetes in rats was induced by injection of STZ (45 mg/kg, body weight) into tail vein. The EtOH extract of the powdered aleurone layer of AP rice was administered orally in diabetic rats for 14 days. In order to find the hypoglycemic effects in the animal model, the body weight, plasma glucose levels, cholesterol, HDL-cholesterol, triglyceride (TG), free fatty acid (FFA), aspartate aminotransferase (AST) and alanine amino- transferase activities (ALT) were determined. Oral administration of 1.0 81kg on the EtOH extract for 14 days resulted in a significant reduction in blood glucose, ALT, TG and FFA. However, in the case of 2.0 g/kg, the hypo-glycemic effects were not considerable. This results suggest that the EtOH extract might induce hypoglycemic effects in STZ-induced diabetic rats due to some photochemical components in the aleurone layer of AP rice.

• Journal of Photoscience
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• v.1 no.1
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• pp.47-52
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• 1994

Effects of HgCl$_2$-treatment on electron transport, chlorophyll a fluorescence and its quenching were studied using isolated barley (Hordeum vulgare L. cv. Albori) chloroplasts. Depending on the concentration of HgCI$_2$, photosynthetic oxygen-evolving activities of photosystem II (PS II) were greatly inhibited, whereas those of photosystem I (PS I) were slightly decreased. The inhibitory effects of HgCl$_2$ on the oxygen-evolving activity was partially restored by the addition of hydroxyamine, suggesting the primary inhibition site by HgCl$_2$2-treatment is close to the oxidizing site of PS tl associated with water-splitting complex. Addition of 50 $\mu$M HgCI$_2$ decreased both photochemical and nonphotochemical quenching of chlorophyll fluorescence. Especially, energy dependent quenching (qE) was completely disappeared by HgCl$_2$-treatment as observed by NH$_4$CI treatment. In the presence of HgCI$_2$, F'o level during illumination was also increased. These results suggest that pH gradient across thylakoid membrane can not be formed in the presence of 0 $\mu$M HgCl$_2$. In addition, antenna pigment composition might be altered by HgCl$_2$-treatment.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.31-34
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• 1997

A new method for the prevention of foreign body-associated infections by controlled release of antibiotic was developed. The polyurethane (PU) matrix containing rifampicin was immobilized with hydrophilic photoreactive polyallylamine (PPA) containing azidophenyl groups. The rifampicin release characteristics and the long-lasting antimicrobial activities of the new material was compared with rifampicin-containing PU matrix without PPA membrane. The release rate of antibiotic from rifampicin-containing PU with PPA membrane significantly decreased as the thickness of PPA membrane was increased. The PPA-immobilized rifampicin-containing PU discs immersed in the PBS for 47 days had an efficient antimicrobial activity against both S. aureus and S. epidermidis.

• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.8-12
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• 1994

The structure-activity studies are described for the photoreaction of naturally occuring psoralen with thymine. Thymine <> psoralen <> thymine photodiadducts from DNA is studied as a model for the charge transfer interaction by the semiempirical methods (PM3-CI-UHF, etc.). The relative structural activities of psoralen, and photoadducts are analyzed in terms of their differing abilities of psoralen and photoadducts are investigated both with regard to their abilities to complex and to intercalate with thymine base. The photoadducts were inferred to be a trans-anti Psoralen(3,4) <> Thymine(5,6) and cis-anti Thymine(5,6) <> (4',5')Psoralen(3,4) <> Thymine.

• Journal of Power System Engineering
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• v.22 no.1
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• pp.72-78
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• 2018

With growing concerns over air pollutions attributed to shipping activities, the international maritime organization has enacted a series of stringent regulations. In particular, MARPOL Annex IV Reg. 16 requires sulfur contents from exhaust gases of marine engines to be progressively reduced. To comply with this regulation, three feasible options have been introduced: using LNG as a marine fuel, using heavy fuel oil with the scrubber system, and using the marine gas oil (a type of low sulfur fuel oil). For the objectives of this paper, the holistic environmental impacts pertinent to these options were investigated and compared in ways that the flows of energy and emission were tracked and quantified through the life cycle of the ship. Research findings obtained from a case study with a large bulk carrier showed that the use of the scrubber system to purify heavy fuel oil would produce relatively fewer amounts of emissions attributing to global warming than other two options. On the other than, the use of LNG would be the way to operate the ship in a cleaner way in terms of reducing the acidification, eutrophication, and photochemical effects. Throughout the analysis, the excellence of life cycle assessment was proven to shift the environmental impact of marine systems from the short-term view to the long-term one.

• Journal of Plant Biology
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• v.36 no.3
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• pp.195-201
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• 1993

The room temperature fluorescence induction of chloroplasts was utilized as a probe to locate the site of inhibition by mercury, copper and zinc on PS II by mercury. Inhibitory effect of Hg2+ on electron transport activity was notable as compared with Cu2+ and Zn2+. At concentrations of HgCl2 over 50 $\mu$M, activities of PS II and whole-chain electron transport decreased more than 70%, while that of PS I decreased about 10~30%. This suggests that PS II is more susceptible to Hg2+ than PS I is. In the presence of diphenylcarbazide (DPC), 50 $\mu$M HgCl2 inhibited the reduction of dichlorophenolindophenol (DCPIP) about 50%. Addition of heavy metals induced marked decrease in maximal variable fluorescence/initial fluorescence [(Fv)m/Fo], but no changes in Fo. With various concentrations of heavy metals, changes of chlorophyll a fluorescence emitted by PS II showed gradual decrease in photochemical quenching (qQ), which indicates an increase in reduced state of electron acceptor, QA. Especially, the addition of HgCl2 caused a notable decrease of qQ. In the presence of 50 $\mu$M CuCl2, energy-depended quenching (qE) was completely reduced, whereas in the presence of 50 $\mu$M CuCl2 and ZnCl2 it was still remained. The above results are discussed on the effects of mercury in relation to water-splitting system and plastoquinone (PQ) shuttle system.

• Rapid Communication in Photoscience
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• v.1 no.1
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• pp.21-24
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• 2012

Influence of gamma rays on the cyanobacterium Synechocystis sp. PCC 6803 cells was investigated in terms of a bidirectional hydrogenase, which is encoded by hoxEFUYH genes and responsible for biohydrogen production. Irradiated cells revealed a substantial change in stoichiometry of photosystems at one day after gamma irradiation at different doses. However, as evaluated by the maximal rate of photosynthetic oxygen evolution, maximal photochemical efficiency of photosystem II, and chlorophyll content, net photosynthesis or photosynthetic capacity was not significantly different between the control and irradiated cells. Instead, transcription of hoxE, hoxH, or lexA, which encodes a subunit of bidirectional hydrogenase or the only transcriptional activator, LexA, for hox genes, was commonly enhanced in the irradiated cells. This transcriptional enhancement was more conspicuously observed immediately after gamma irradiation. In contrast, hydrogenase activities were found to somewhat lower in the irradiated cells. Therefore, we propose that transcription of hox genes should be enhanced by gamma irradiation in a LexA-mediated and possibly photosynthesis-independent manner and that this enhancement might not induce a subsequent increase in hydrogenase activities, probably due to the presence of post-transcriptional and/or post-translational regulatory mechanisms.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.92-97
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• 1989

This study investigated the effects of high light intensity (100 KLw) and high temperature (45 ℃, dark) on enzyme (glucose-6-phosphate dehydrogenase, acid phosphatase, catalase, peroxidase, and proteinase) activities and characteristics of Panax ginseng C.A. Meyer leaves. Enzyme activity and protein content decreased rapidly under treatment with high light intensity In P ginseng the thermal stabilities of catalase and peroxidase were high (above 70%), and the coagulation rates of soluble proteins were low (below 17%). Therefore, the decrease in enzyme activity and protein content was not caused by increase in leaf temperature due to the high light intensity, but by increase in proteolytic activities. The photochemical formation rate of superoxide radical (O-2) was higher in the P ginseng leaf extracts than in Solanum nigmm, and was accelerated by addition of crude saponin to the buffer extracts.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.615-617
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• 2003

Carbon monoxide (CO) is one of the important trace gases because its concentration in the troposphere directly influences the concentrations of tropospheric hydroxyl (OH), which controls the lifetimes of tropospheric trace gases. CO traces the transport of global and regional pollutants from industrial activities and large scale biomass burning. The distributions of CO were analyzed using the MOPITT data for East Asia, which were compared with the ozone distributions. In general, seasonal CO variations are characterized by a peak in the spring, which decrease in the summer. The monthly average for CO shows a similar profile to that for O$_3$. This fact clearly indicates that the high concentration of CO in the spring is possibly due to one of two causes: the photochemical production of CO in the troposphere, or the transport of the CO into East Asia. The seasonal cycles for CO and O$_3$ in East Asia are extensively influenced by the seasonal exchanges of different air mass types due to the Asian monsoon. The continental air masses contain high concentrations of O$_3$ and CO, due to the higher continental background concentrations, and sometimes to the contribution from regional pollution. In summer this transport pattern is reversed, where the Pacific marine air masses that prevail over Korea bring low concentrations of CO and O$_3$, which tend to give the apparent summer minimums.

• Journal of Photoscience
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• v.8 no.1
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• pp.1-7
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• 2001

The deteriorative effect of ultraviolet-B(UV-B) radiation on photosynthesis was assessed by the simultaneous measurement of O$_2$ evolution and chlorophyll(Chl) fluorescence in green pepper. UV-B was given at the intensity of 1 W$.$m$\^$-2/, a dosage often encountered in urban area of Seoul in Korea, to detached leaves. Both Pmax and quantum yield of O$_2$ evolution was rapidly decreased, in a parallel phase, with increasing time of UV-B treatment. Chl fluorescence parameters were also significantly affected. Fo was increased while both Fm and Fv were decreased. Photochemical efficiency of PSII(Fv/Fm) was also declined, although to a lesser extent than Pmax. Both qP and NPQ were decreased similarly with increasing time of UV-B treatment. However, PS I remained stable. The addition of lincomycin prior to UV-B treatment accelerated the decline in Fv/Fm to some extent, suggesting that D1 protein turnover may play a role in overcoming the harmful effect of UV-B. The amount of photosynthetic pigments was less affected than photosynthetic response in showing decline in Chl a and carotenoids after 24 h-treatment. Presumptive flavonoid contents, measured by changes in absorbance at 270 nm , 300 nm and 330nm, were all increased by roughly 50% after 8 h-treatment. Among antioxidant enzymes, activities of catalase and peroxidase were steadily increased until 12h of UV-B treatment whereas ascorbate perxidase, dehydroascorvate reductase and glutathione reductase did not show any significant change. The results indicate that deteriorative effect of UV-B on photosynthesis precedes the protection exerted by pigment synthesis and antioxidant enzymes.