• Title/Summary/Keyword: pigment bleaching

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Impacts of Ultraviolet-B Radiation on Rice-Field Cyanobacteria

  • Sinha, Rajeshwar P.;Hader, Donat-P.
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.439-441
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    • 2002
  • Cyanobacteria are the dominant micro flora in rice-fields, contributing significantly to fertility as a natural biofertilizer. Recent studies show a continuous depletion of the stratospheric ozone layer, and the consequent increase in solar UV-B (280-315 nm) radiation reaching the Earth's surface. UV-B radiation causes reduction in growth, survival, protein content, heterocyst frequency and fixation of carbon and nitrogen in many cyanobacteria. UV -B induced bleaching of pigments, disassembly of phycobilisomal complexes, thymine dimer formation and alterations in membrane permeability have also been encounterd in a number of cyanobacteria. However, certain cyanobacteria produce photoprotective compounds such as water soluble colorless mycosporine-like amino acids (MAAs) and the lipid soluble yellow-brown colored sheath pigment, scytonemin, to counteract the damaging effects of UV-B. Cyanobacteria, such as Anabaena sp., Nostoc commune, Scytonema sp. and Lyngbya sp. were isolated from rice fields and other habitats in India and screened for the presence of photoprotective compounds. A circadian induction of the synthesis of MAAs by UV -B was noted in a number of cyanobacteria. Polychromatic action spectra for the induction of MAAs in Anabaena sp. and Nostoc commune also show the induction to be UV-B dependent peaking at 290 nm. Another photoprotective compound, scytonemin, with an absorption maximum at 386 nm (also absorbs at 300, 278, 252 and 212 nm), was detected in many cyanobacteria. In conclusion, a particular cyanobacterium having photoprotective compounds may be a potent candidate as biofertilizer for crop plants.

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Selectivity of Bleaching Herbicides Caused by Physiological Differences between Rice and Barnyardgrass (벼와 피의 생리적(生理的) 차이(差異)에 의한 백화형(白化型) 제초제(除草劑)의 선택성(選擇性))

  • Na, J.Y.;Kim, J.S.;Kim, T.J.;Cho, K.Y.;Pyon, J.Y.
    • Korean Journal of Weed Science
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    • v.12 no.2
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    • pp.89-101
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    • 1992
  • In this study, various physiological and biochemical experiments were conducted to know whether the selectivity between rice and barnyardgrass treated with bleaching herbicides containing diphenyl ether compounds was also partly based on their basic physiological proterties such as peroxidation ability, membrane stability or antioxidant system. It seemed to be partly based on the differences of their physiological characteristics that barnyardgrass was commonly more susceptible to most of the bleaching herbicides than rice. The scenescence of intact leaf segment was more rapid in barnyardgrass than in rice, indicating that barnyardgrass is weak at early stage. Also pigment metabolic ability, antioxidant enzyme activities(peroxidase, catalase, superoxide dismutase, glutathione reductase) and antioxidant content (tocopherol, ascorbic acid, glutathione, carotenoids) were lower in barnyardgrass on the basic of fresh weight. However, lipoxygenase activity and the content of unsaturated fatty acid which is vulnerable to oxygen radicals were higher in barnyardgrass, suggesting that barnyardgrass seedling bave a properties easy to be peroxidized. The differences of PPIX (protoporphyrin IX) or carotenoid content, which are the primary substances inducing herbicide activity, were not related to the selectivity between rice and barnyardgrass.

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365 nm LED laser treatment on beagle for gingival whitening without gum dermabrasion (잇몸 박피술 없는 치은 미백을 위한 비글에서 365 nm LED 레이저 치료)

  • Lee, Sung-Ho;Kim, Ryun Kyung;Seo, Na-Ri;Lim, Ho-Kyung;Byun, Soo-Hwan;Lim, Young-Joon;Kim, Soung-Min;Lee, Jong-Ho
    • Journal of Dental Rehabilitation and Applied Science
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    • v.32 no.2
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    • pp.117-122
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    • 2016
  • Purpose: Gingival whitening is one of dental treatment purposes which is close to treating aesthetic disorders. Initial gingival whitening treatment was done by dermabrasion using a high power Diode Laser. However, this treatment method cannot be free from any infection or pain after the treatment. Therefore, we have decided to progress gingival whitening treatment using a low power LED laser. Materials and Methods: The laser was irradiated on pork meat then the safety of output power, temperature change and skin denaturalization was measured. Bison 365 nm LED laser was irradiated on oral mucosal pigment of a 15 - 20 kg beagle for 15 min for 1 - 2 weeks, one or two times each. Any pigment loss was checked through Hematoxyline-Eosin staining. Results: The melanin pigments at the area of 365 nm LED Laser irradiation were decreased. Conclusion: The 365 nm LED Laser proposed in this study is considered to compensate the bleaching effect achieved by either using Diode laser or surgical methods.

The Effects of Ultrastructure with Onion (Allium cepa) Skin Extracts on Human Hair Dyeing (양파(Allium cepa) 외피 추출물이 모발의 미세구조에 미치는 효과)

  • Na, Yun-Young;Cheong, Min-Ju;Roh, Young-Bok
    • Applied Microscopy
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    • v.38 no.1
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    • pp.35-41
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    • 2008
  • Onions are commonly available and easily processed, and since their skins are thrown away they could be very useful materials from the viewpoint of environmental preservation. This study aimed to process onion skins into the state of powder and look into the optimum condition for hair dyeing by decoloring virgin hair four times and observing the hair dyeing quality and its mechanical and morphologic changes by the different condition of onion skins in duration, temperature, density, pH, and mordant treatment. The observations of hair surface through scanning microscopy showed the formation of cuticle layer, though in a little blown-up state in the case of the hair dyed with onion skin application, when compared with bleaching hair with the completely dissolved cuticle layer. According to the above findings of experiments, the dyeing quality of the hair dyes with onion skin application was excellent, the dyeing was also feasible without mordants, and the use of Fe as the mordant increased dyeing exhaustion more, which would make it an effective hair dye. These results of the experiments indicate that the natural pigment extracted from onion skins can be actually used for hair dyeing from the viewpoints of the dyeing quality and the skin treatment.

Study on the Enzyme Activity in Leaf-Burning Disease of Panax ginseng C.A. Meyer (인삼엽요병에서 효소활성도의 변화)

  • 양덕조;김명원
    • 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.

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Studies on Packaging of Chillies (Capsicum annum) in Flexible Films, and Their Laminates (유연포장재료(柔軟包裝材料)를 이용(利用)한 고추 포장(包裝)에 관(關)한 연구(硏究))

  • Chang, Kyu-Seob;Kim, Ze-Uook
    • Applied Biological Chemistry
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    • v.19 no.3
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    • pp.145-154
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    • 1976
  • Studies have been carried out to design a suitable consumer size package from flexible packaging material to hold 100 grams of Chilli powder and 250 grams of whole chilli which are moisture and color sensitive. 1. Sorption characteristics of the chilli powder has revealed that moisture sorption is rapid above 55 per cent R.H., and the product is fairly hygroscopic. Further, an equilibrium moisture content of about 15 per cent at 70 per cent R.H., appears to be critical from the point of microbial spoilage of chilli powder. 2. Studies on the colour (Capsanthin) changes of chilli powder equilibriated to different moisture content, have revealed that colour changes during storage is greatly influenced by the moisture content and temperature decreases the capsanthin content of chilli during storage. 3. From the studies, it can be inferred that the sunlight exhibits pronounced effect in bleaching of colour and brings about maximum discolouration of the red pigment in chilli. 4. From the packaging and storage studies of chilli powder in different flexible films, it can be concluded that for long-term storage, the aluminium foil laminate is unique in offering maximum protection from various physico-chemical changes. For short-term storage and for fairly good moisture and colour protection, amber or black polyethylene, high-density polyethylene and Saran/Cello/Saran poly laminate pouches appear to be suitable alternatives.

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Gingival pigmentation treatment using Er;YSGG laser (Er;YSGG 레이저를 이용한 치은 색소침착 제거 증례보고)

  • Kim, Hyunjong
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.30 no.2
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    • pp.53-58
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    • 2021
  • The attractiveness of the gingiva is determined by its color, shape, and the shape and location of the boundary between the teeth and the gingival tissue. The standards beauty, balance, and health of the gingiva are all different, but the general public would agree that a coral pink gingiva is more beautiful than black or brown gingiva. Hence, one would be able to smile more confidently in public if he or she receives a gingival pigmentation removal surgery that changes the color of black or brown gums to a beautiful pink color with relative simplicity. The color of one's gingiva varies from pale pink to deep bluish purple, depending on many health components. The most prominent among these include the vascular supply, epithelial thickness, the degree of keratinization, and the presence of pigment in the epithelium. Melanin, carotene, reduced hemoglobulin, and oxyhemoglobulin are the main pigments contributing to the normal color of the oral mucosa. The health of one's gingival tissue are essential for an attractive smile. Excessive melanin deposits in the basal and early basal layers of the epithelium stored in the form of melanosomes frequently cause pigmentation. Although there are many different procedures to remove this pigmentation, the it was removed using the Er;YSGG laser. It is my wish that, through this case study, many people