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Volume 67 (1998)
- Issue 6 Pages 437-
- Issue 5 Pages 361-
- Issue 4 Pages 265-
- Issue 3 Pages 163-
- Issue 2 Pages 91-
- Issue 1 Pages 1-
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Volume 67, Issue 2
Displaying 1-12 of 12 articles from this issue
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Studies on the dissolution of silk fibroin. (IX)AKIYOSHI AJISAWA1998 Volume 67 Issue 2 Pages 91-94
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSFibroin was dissolved in a solution of calcium chloride and water (molar ratio 1:8) and a solution of calcium chloride, water and ethanol (molar ratio 1:8:2) which was made by adding 2 mol of ethanol to the former solution. Fibroin insoluble in the calcium chloride aqueous solution at 20 to 30°C (approx room temperature) for 240 to 720hr, but was dissolved in the solution to which ethanol was added. Such longe-term treatment, however, involves cost problems. In order to cope with such problems, fibroin was treated with a calcium chloride aqueous solution at 40 to 60°C for 1hr. The fibroin was dissolved to 0.7 to 3.3%. Treatment in the solution to which ehtanol was added at 55°C for 1hr, vesulted in complete dissolution, which was approximately 35 times more likelythan with the calcium aqueous solution. Based on these results, the solution of calcium chloride, water and ethanol (molar ratio 1:8:2) was considered to be very promising as a solvent of bio-material fibroin, from a viewpoint of industrial application.View full abstractDownload PDF (476K) -
Physico-chemical studies on cocoon reelability (VI)AKIYOSHI AJISAWA1998 Volume 67 Issue 2 Pages 95-99
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSWhen exposed to ultraviolet rays of wavelength 360nm (visible rays were filtered), cocoons fluoresced colors such as yellow. Yellow fluorescent cocoons have higher reelability percentages than violet fluorescent cocoons. A cocoon lot was artificially divided into high-reelability percentage lots and low-reelability percentage sub-lots. The cocoon fluorescent color distribution of the respective sub-lots was observed and solubility of cocoon layer sericin was measured, and both were compared. In the results, reelability percentage could not be determined by fluorescent color distribution in the case of cocoon lots of the various mixed fluorescent color cocoons. On the other hand, cocoon layer sericin separated by fluorescent color was observed. Yellow fluorescent sericin was more soluble than violet in boiling water. When treated with boiling water, this yellow substance was rapidly dissolved from silk sericin. As for adhesion of cocoon filaments, which causes problems during the reeling process, the soluble yellow substance was favorable for separation of adhesive cocoon filaments. Further, it was considered that violet fluorescent cocoon sericin was slow in separation of cocoon filaments and worse than yellow fluorescent cocoon sericin. Based on the above reason, the author proposes a possible reeling method to improve reelability in which a cocoon lot is grouped into sub-lots depending on fluorescent color observed under ultraviolet rays.View full abstractDownload PDF (558K) -
KOUKICHI NAGASAKA, KEISUKE MASE, EIJI OKADA, TOSHIO YAMAMOTO1998 Volume 67 Issue 2 Pages 101-107
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSIn order to find a simple and adequate index to quantify dispersal activity of silkworm larvae (Bombyx mori L.), dispersal processes were analyzed with the simplest diffusion model. Coordinates of 14-66 newly hatched larvae released in a 25°C incubator without light were recorded every 5 minutes. If all individuals moved randomly at a constant intensity, the following two predictions should be satisfied. (1) The variances of distributions increase in direct proportion to time. (2) Individuals spread in a normal distribution. The results of analyzing coordinates of larvae were consistent with these two predictions, demonstrating that the dispersal of silkworm larvae is a random process. Therefore, dispersal activity can be evaluated with the diffusion coefficient D of the simplest diffusion model. Analysis of variance test for D's of 6 strains showed that there were significant differences among the strains, but neither between generations nor between batches within each strain. This implies that the D is an appropriate index to evaluate dispersal activity of each strain and is applicable to genetic analyses.View full abstractDownload PDF (2618K) -
YOSHIAKI TANAKA1998 Volume 67 Issue 2 Pages 109-115
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSThe effect of ecdysone supplemented to the artificial diet on the larval development of non-molting glossy mutant silkworm, Bombyx mori, was investigated. When the first-instar larvae of nm-g mutant were isolated on day 6 after hatching and they were reared on artificial diets supplemented with various concentrations of either ecdysone or 20-hydroxyecdysone (20-OH-E), about 90% of the larvae fed on ecdysone≥200ppm molted to the second-instar, but only 60% of the larvae fed on 20-OH-E could molt to the second instar even though they fed on 400ppm 20-OH-E. The second- and third-instar larvae of nm-g mutant induced by 200ppm ecdysone molted to the next instar when they were transferred to the diet supplemented with ecdysone at the early stage of each instar. But the third- and fourth-instar larvae of nm-g mutant molted to larval-pupal intermediate or began to spinning when they were transferred to the diet supplemented with ecdysone at the late stage of each instar. These results suggest that the dietary administration of ecdysone at an appropriate stage of each instar induces larval ecdysis effectively in the nm-g mutant larvae.View full abstractDownload PDF (2364K) -
KEIKO SAKATA, NAOKO NAGASHIMA, AKIRA KATAYAMA1998 Volume 67 Issue 2 Pages 117-122
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSCarminic acid was extracted from cochineal on the market and purified according to the procedure described in a literature. The dissociation constants of some acidic groups in the pigment, 7-carboxylic group, 3- and 6-hydroxyl groups, were determined from the results of pH titration curve of aqueous solutions of the pigment with NaOH at 25°C. The effects of pH and an addition of aluminum ion on the absorption spectra of aqueous solutions of the pigment were examined. An aluminum-mordanted silk fibroin film was dyed with the pigment and the absorption spectrum of the dyed film was examined. By the results obtained in this paper, it was concluded that an aluminum complex of the pigment may be formed between 7-carboxylic and 6-hydroxyl groups on the aluminum-premordanted silk fibroin film. Aluminum- or tin(II)-mordanted silk fabrics were dyed with the pigment and the surface colors of the dyed fabrics were shown on the a*b* diagram of the L* a* b* colorimetric system.View full abstractDownload PDF (780K) -
NAOKO NAGASHIMA, KEIKO SAKATA, AKIRA KATAYAMA1998 Volume 67 Issue 2 Pages 123-127
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSShikonin was extracted from the dried roots of Lithospermum erythrohizon on the market with hot water and purified by recrystallization from benzene. The dissociation constants of two hydroxyl groups in the pigment molecule were estimated by the results of visible absorption spectra of aqueous solutions of shikonin at various pH's. The effects of an addition of aluminum ion on the visible absorption spectra of shikonin in a methanol solution were examined. An aluminum-premordanted silk fibroin film was dyed with shikonin and the visible absorption spectra of the dyed film was examined. By the results, it was concluded that both 5- and 8-hydroxyl groups in the pigment may form aluminum chelates with the neighboring carbonyl groups in the methanol solution and on the silk fibroin film, respectively. Aluminum- or tin (II)-premordanted silk fabrics were dyed with sikonin from water-ethanol solution (1:4, V/V). The surface colors of the dyed fabrics were shown on the a* b* diagram of the L* a* b* colorimetric system.View full abstractDownload PDF (617K) -
LIANG JUN ZHU, JU MING YAO, KIYOSHI HIRABAYASHI1998 Volume 67 Issue 2 Pages 129-133
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSWhen the silkworms spun in high humidity, the molecular structure of sericin was changed from random coil to β-structure and the sericin underwent gelation. The surface of the cocoon filament was covered with dried sericin, and the stripping resistance of the cocoon filament was strengthened due to the sericin's increased strength and gumming force. As a result it was difficult to dissociate the cocoon filament and reelability was poor. On the other hand, under moderate cocooning conditions, sericin gelation was avoided. Gumming force and stripping resistance were less, making it easy to dissociate the cocoon filament and ensuring good reelability.View full abstractDownload PDF (581K) -
Ritsuko MURAKAMI, Akira SHIRATA1998 Volume 67 Issue 2 Pages 135-142
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSThe toxic components producted by Myrothecium roridum showed different intensity of toxicity against various plants including Slidago altissima L., Artemisia princes Pamp., Rumex crispus L. and Setaria viridis (L.) P. etc.. Trifolium repens L., Cayytatia japonica (Thunb.) Gagn. and Oenothera odorata Cav. are very sensitive against the toxic components and Plantago asiatica L., Houttuynia cordata Thunb., Miscanthus sinensis Anders and Pheioblastus numilis (Mitford) Nakai are non-sensitive. The results suggest that the toxic components have selective toxicity to various plants. Optium medium and temperature for production of the toxic components is potato sucrose agar medium and 25-30°C. The components are extracted easily with water and sterilized at 80°C for 3 minutes. The toxicity of the components against plants depends on concentration of the solution and addition of spreader. These results support that the components apply for the herbicide.View full abstractDownload PDF (2836K) -
NOBUHIRO MATSUKI, TOSHIMASA MITAMURA, NORIO DOI1998 Volume 67 Issue 2 Pages 143-145
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSWood vinegar is useful for the control of plant pathogenic fungi against sapling of needleleaf tree. We examined effect of wood vinegar to fungus disease of silkworm.
Wood vinegar made from mulberry branches and marketing wood vinegar named Junseimokusakueki were used for the examination. Two types of wood vinegar checked germination of conidum and restrained growth of hypha of Beauveria bassiana. Spray of wood vinegar to rearing bed restrained fungus disease of silkworm, and didn't influence quantitative character of silkworm.
Wood vinegar should be useful for the control of fungus disease of silkworm.View full abstractDownload PDF (407K) -
SHIGETO SHIMIZU, MASANOBU OHURA, TATSUO MITSUISHI1998 Volume 67 Issue 2 Pages 147-150
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSDownload PDF (5048K) -
YILE PAN, KENGO OSHIGANE1998 Volume 67 Issue 2 Pages 151-153
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSDownload PDF (1939K) -
MIKIHIKO MIURA, HIDEAKI MORIKAWA, KENJI SHO, MASAYUKI IWASA, NANAE TOF ...1998 Volume 67 Issue 2 Pages 155-158
Published: April 27, 1998
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSDownload PDF (492K)
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