• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.82-87
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• 2013

A study on desorption and regeneration characteristics for silver ions adsorbed onto crab shells was carried out by means of Nitric acid soultion which was selected as the best desorbing agent. Desorption efficiency for silver ions was the highest as about 96% at the 1.0M of Nitric acid concentration. Also, silver ions was almost desorbed below 1.0 of S/L(mg/mL) ratio which is defined as the ratio of adding amount of adsorbent and volume of desorbing agent and most of desorption process was completed within 60min. And removal efficiency of reused crab shells for silver ions was maintained as about 92% until the 2nd cycle.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.208-214
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• 2000

A bacterial strain producing extracellular chitosanase was isolated from crab shells and identified as a member of the genus Aureobacterium The production of chitosanase was proportionally related to the microbial growth, induced by the presence of chitosan, and repressed by glucose at 0.5% (w/v) concentration or higher. The optimal culture conditions for the production of chitosase were 3$0^{\circ}C$ and pH 7.0. Among the nitrogen sources tested, incubation with 0.25% (w/v) concentrations of tryptone and casitione showed the best production of chitosanase. The chitosanase of Aureobacterium sp. YL produced chitobiose as a major product and glucosamine, chitotriose, chitotetraose, and chitopentaose as minor products from chitosan.

• Animal Systematics, Evolution and Diversity
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• v.36 no.4
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• pp.391-395
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• 2020

This study reports the pagurid hermit crab Porcellanopagurus japonicus in Korean waters for the first time. This species has a right cheliped larger than the left one, reduced and globular abdomen, and symmetrical uropods. Porcellanopagurus japonicus is similar to P. nihonkaiensis, a previously reported congeneric species in Korea, but also has distinguished morphological and ecological characters. There are currently issues with the Korean scientific name for P. japonicus, we suggest a reasonable Korean scientific name of this organism with its etymology. In addition, this species inhabits bivalve shells, which is not a typical habitat for hermit crabs, and the unique habitats of this and several other Korean hermit crabs are reviewed.

• Journal of the Korean Applied Science and Technology
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• v.10 no.2
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• pp.41-47
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• 1993

Chitin was isolated from crab shells by modified Hackman's method, which was treated again with aqueous sodium hydroxide solution to give alkali chitin(sodium alkoxide of chitin). And after, the alkali chitin is allowed to react with monochloroacetic acid to synthesize 6-O-(carboxymethyl) chitin [CM-Chitin] under diminished pressure. In order to synthesize high performance CM-Chitin as hygroscopic agent, it was measured that the yield and degree of subsititution of each CM-Chitin according to molar ratio(monochloroacetic acid equivalent mol/N-acetyl-D-glucosamine residue) and their moisture-absorption and moisture-release properties were measured and compared with those of hyaluronic acid. The moisture-absorption and moisture-release properties of CM-Chitin, especially 0.8 in degree of substitution, were found quite similar to those of hyaluronic acid. The preliminary results show that CM-Chitin might be used as hygroscopic agent instead of hyaluronic acid in field of cosmetics.

• Journal of the Korean Ceramic Society
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• v.55 no.6
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• pp.570-575
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• 2018

Hydroxyapatites (HAps) were synthesized using the powdered waste of fishery products, i.e., fish scales and crab shells, as starting materials. HAp was synthesized by a wet-chemistry method followed by calcination at 600 and $800^{\circ}C$. Calcined crabshell powder revealed a single HAp phase and fine powder, while calcined fish-scale powder showed a ${\beta}-TCP$ secondary phase, even at the higher calcination temperature. Dense HAp pellets were obtained from the crab-shell powder by spark plasma sintering at $1000^{\circ}C$ for 10 min under applied pressures of 40 and 80 MPa in a vacuum state, giving sample densities of 2.93 and $3.06g/cm^3$, respectively. The estimated grain size of HAp was $448{\pm}96$ and $283{\pm}59nm$ for applied pressures of 40 and 80 MPa, respectively. In contrast, the HAp obtained using the pressureless sintering technique showed excessive grain growth without further densification.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.222.2-223
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• 2003

Renal dipeptidase (RDPase, EC 3.4.13.19), an ectoenzyme of renal proximal tubules, is covalently bound to outer leaflet of lipid bilayer via glycosylphosphatidylinositol (GPI)-anchor. Chitin is a major component of the shells of crustacea such as crab, shrimp and crawfish. This study was conducted to examine the effect of chitosan on RDPase release from renal proximal tubules. Nitric oxide (NO), highly reactive free radical, inhibits the release of RDPase from porcine proximal tubules. (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.319.2-319.2
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• 2002

Chitin is a major component of the shells of crustacea such as crab. shrimp and crawfish. Renal dipeptidase (RDPase. EC 3.4.13.19), an ectoenzyme of renal proximal tubules. is covalently bound to outer leaflet of lipid bilayer via glycosylphosphatidylinositol (GPI)-anchor. The biological role of RDPase was suggested as the hydrolysis of dipeptide into free-amino acids before renal reabsorption. The underlying biochemical mechanism of decreased RDPase release was suggested as nitric oxide (NO) production. (omitted)

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.67-72
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• 2005

To achieve demineralization of crab shell waste by chemical and biological treatments, lactic acid and lactic acid bacterium were applied. In 5.0 and $10\%$ lactic acid, pH rapidly decreased from 6.8 to 4.2 and from 4.5 to 2.4 at day 3, respectively, and thereafter the pH remained at an almost constant level. In a $10\%$ lactic acid bacterium inoculum, pH lowered to 4.6 at day 5. Relative residual ash content rapidly decreased to 49.1 and $16.4\%$ in 5 and $10\%$ lactic acid treatments, respectively, for the initial 12 h. In 2.5, 5 and $10\%$ lactic acid bacterium inoculums, relative residual ash content rapidly decreased to 55.2, 40.9 and $44.7\%$, respectively, on the first day. Residual dry masses were 76.4, 67.8 and $46.6\%$ in 2.5, 5 and $10\%$ lactic acid treatments, respectively, for the initial 12 h. After a one-time exchange of the lactic acid solution, in the $5.0\%$ lactic acid treatment, residual dry mass rapidly decreased from 66.0 to $41.4\%$. In 2.5, 5 and $10\%$ lactic acid bacterium inoculums, residual dry masses decreased to 67.6, 57.4 and $59.6\%$ respectively, on the first day. Protein contents after demineralization ranged from $51.3{\sim}54.7\%$ in the chemical treatments and decreased to $32.3\%$ in the lactic acid fermentation process. A negative relationship was shown between pH and demineralization rate in lactic acid and lactic acid bacterium treatments. These results suggest that lactic acid fermentation can be an alternative for demineralization of crab shells, even though the rate and efficiency of the demineralization is lower than the chemical treatment.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.83-92
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• 1999

Chitosan was prepared from chitin which was abstracted from wasted crab shells. Then itaconic acid was graft-copolymerized onto chitosan using ceric ammonium nitrate as a reaction initiator. To investigate the optimal grafting conditions, the influences of several factors on the grafting were studied, i. e., the concentrations of CAN and itaconic acid, the reaction temperature and time. And to find out its flocculation ability. the flocculation test was carried out with a metal plating factory waste water. The state of graft-copolymer was identified through IR spectra analysis. The optimal grafting conditions and flocculation results were shown to be : concentration of ceric ammonium nitrate is $3.5{\times}10^3M$, reaction temperature is $40^{\circ}C$ and reaction time is 4hrs with 0.25M of the monomer(itaconic acid). Though flocculation tests using chitosan, grafted chitosan and cation, CODcr. metal ions removal rates were measured. The order of superiority is Itaconic acid grafted chitosan>Chitosan>Cationic polymer.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.485-488
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• 2010

Purpose: Paragonimiasis is infectious disease occurred by Paragonimus Westermani, which invades into human body as a final host. Habitual eating the freshwater crab or crawfish unboiled is one of the reason of infection. Paragonimiasis raged in 1970s in Korea, Japan, China and other Asian countries but the incidence decreased rapidly. Once people eat infected second host, parasite penetrates the duodenal wall and migrates to the lung. During this migration period, the parasite can migrate to other organ, such as brain, spinal cord, liver and subcutaneous tissue, but the cases are rarely reported. The objective of our study is to present our experience of the ectopic migration of parasite to the subcutaneous tissue of the abdomen, which was easily treated with excision and Praziquantel medication. Methods: A 59-year-old woman who likes eating unboiled freshwater crab was diagnosed as Paragonimiasis 15 months ago. Her symptoms were fever and cough, and she was treated with Praziquantel medication. 3 months after discharge, she visited our hospital with left pleuritic chest pain, cough with fever, and palpable mass formation on left lower quadrant of the abdomen. Wedge resection of the left lung and Praziquantel medication was maintained for a week. Nevertheless, fever persisted after the treatment. The patient received total excision of the abdominal soft tissue mass, and the fever was relieved. Results: Pathologic findings of the mass showed multiple cyst and abscess formation with crystal structure which is suspicious parts of the parasite or calcified egg shells. Uncontrolled fever was relieved after the operation, and there was no evidence of recurrent Paragonimiasis and ectopic migration for 1 year follow up period. Conclusion: Ectopic migration of Paragonimus is rare, but multiple organ can be involved. Patient with Paragominiasis who was refractory in fever control after Praziquantel medication or surgical evaluation of the lung should be considered as ectopic migration of the Paragonimiasis.