• 제목/요약/키워드: Buffer content

검색결과 275건 처리시간 0.024초

SiOx 함량에 따른 CB/SiOx/C 음극재의 전기화학적 특성 (Electrochemical Performance of CB/SiOx/C Anode Materials by SiOx Contents for Lithium Ion Battery)

  • 김경수;강석창;이종대;임지선
    • 공업화학
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    • 제32권1호
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    • pp.117-123
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    • 2021
  • 본 연구에서는 실리콘 산화물, 소프트 카본, 카본 블랙을 혼합하여 복합체를 제조하였으며, 이차전지의 음극 특성을 고찰하였다. 이때, 소프트 카본 음극재의 용량 향상을 위하여 첨가된 실리콘 산화물 함량을 0, 6, 8, 10, 20 wt%로 달리하였으며, 카본 블랙은 실리콘 산화물의 부피 팽창 완화를 위한 구조 안정제로 첨가되었다. 제조된 CB/SiOx/C 복합체의 물리적 특성은 XRD, SEM, EDS 및 분체 저항 분석을 통하여 조사되었다. 또한 제조된 복합체의 전기화학적 특성은 리튬 이차전지의 충·방전 사이클, 율속 및 임피던스 분석을 통하여 관찰되었다. CB/SiOx/C 복합체는 카본 블랙 첨가에 의하여 실리콘 산화물의 부피 팽창을 완화시킬 수 있는 내부 공동이 형성되었으며, 카본 블랙과 실리콘 산화물 입자가 고르게 분포되었다 형성된 내부 공동은 실리콘 산화물 함량이 8 wt% 미만에서는 낮은 초기 효율 보이며, 20 wt% 이상에서는 낮은 사이클 안정성을 보였다. 실리콘 산화물이 10 wt% 첨가된 CB/SiOx/C 복합체는 537 mAh/g 초기 방전 용량, 88 %의 용량 유지율과 2C/0.1C에서 79 율속 특성을 보였다. 이는 소프트 카본 음극재의 용량을 향상시키기 위해 실리콘 산화물을 첨가하였고, 실리콘 산화물의 부피 변화를 완충하기 위해 구조 안정제로 카본 블랙을 첨가하였다. CB/SiOx/C 복합체를 고효율의 음극재로 사용하기 위해 최적의 실리콘 산화물 함량 및 구조 안정제로서의 카본 블랙의 메커니즘을 논의하였다.

Semen Quality Assessment of Local Katjang and Cross-Bred (Katjang × German) Bucks

  • Noran, A.M.;Mukherjee, T.K.;Abdullah, R.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권4호
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    • pp.445-449
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    • 1998
  • Semen quality was compared between the local Katjang and the cross-bred (local Katjang ♀ ${\times}$ German Fawn ♂) bucks. There were on significant genotypic differences in semen characteristics of concentration (first ejaculate : $6.19{\pm}1.30$ -versus $6.33{\pm}1.40{\times}10^9/ml;$second ejaculate: $5.82{\pm}1.10$ - versus $5.68{\pm}1.45{\times}10^9/ml$, for Katjang and the cross-breds, respectively), percentage live (first ejaculate: $77.61{\pm}1.33%$ versus $77.81{\pm}0.53%$; second ejaculate: $81.97{\pm}1.59%$ versus $82.74{\pm}0.96%$, for Katjang and cross-breds, respectively) and percentage of normal sperms (first ejaculate: $12.54{\pm}3.88%$ versus $26.45{\pm}3.83%$; second ejaculate: $38.68{\pm}3.65%$ versus $28.54{\pm}4.38%$, for Katjang and cross-breds, respectively), with the exception of seminal volume and sperm motility. Means of all variables were within the values reported for other goat breeds, In contrast, the differences in semen characteristics between the first and second ejaculations of both genotypes were more distinct, the second ejaculations always had more volume, more normal sperms and better sperm motility but less sperm concentrations. Removing the seminal plasma and replacing it with tris-citrate buffer greatly prolonged the viability of sperms of both genotypes when stored at $5{^{\circ}C}$. Sperm motility seens to be a good indicator of sperm viability. However, the sperms of the corss-bred bucks withstood the washing process better and their swimming abilities were superior ($8.12{\pm}0.46mm/min$) when compared to those of the local Katjang breed ($5.42{\pm}0.49mm/min$). The higher content of calcium ions in their seminal plasma (first ejaculate: $10.5{\pm}0.8$ versus $10.6{\pm}0.8mg/100ml$;second ejaculate: $15.3{\pm}0.8$ versus $16.1{\pm}0.8mg/100ml$, for Katjang and cross-breds, respectively) means that in natural matings the sperms of the cross-breds would be at an advantage compared to those of the local Katjang, since calcium ions reportedly initiate acrosomal reactions.

습식분쇄하여 분무건조한 초미세 분말 칼슘의 품질특성 (Quality Characteristics of Spray Drying Microparticulated Calcium after Wet-grinding)

  • 한민우;윤광섭
    • 한국식품과학회지
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    • 제41권6호
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    • pp.657-661
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    • 2009
  • 해조칼슘을 습식분쇄한 초미세액상칼슘을 분무건조하여 부형제 종류에 따른 분말칼슘의 품질특성을 알아보고자 gum arabic, cyclodextrin, Na-caseinate를 첨가하여 품질특성을 비교하였다. 분무건조한 초미세분말칼슘의 수분함량은 2% 내외의 안정한 분말을 얻을 수 있었고, 색도는 원료인 해조칼슘보다 L값은 높았으며, b값은 감소하는 것으로 나타났다. 입자크기는 당류의 부형제 첨가로 초미세 크기로 분쇄되는 것을 확인할 수 있었으며, gum arabic을 첨가하여 제조한 초미세액상칼슘을 분무건조한 분말이 식초와 pH에 대한 용해도에서 가장 우수한 것으로 나타났다. 칼슘함량은 해조칼슘분말이 28%의 칼슘함량을 나타내었고, 부형제를 달리하여 제조한 초미세액상칼슘을 분무건조한 분말은 27% 내외로 비슷한 칼슘함량을 나타내어, 습식분쇄나 분무건조 공정에서 칼슘의 손실은 없는 것으로 나타났다. 흡습에 대한 안정성실험에서는 해조칼슘분말이 흡습에 안정하였으며, gum arabic을 첨가하여 분무건조한 분말이 흡습이 많이 발생하였다. 전자주사 현미경 관찰을 통하여 습식분쇄로 입자크기가 작아지는 것을 확인할 수 있었고, gum arabic을 사용하여 얻은 초미세칼슘분말이 단백질계나 사용하지 않았을 때보다 더 균일한 입자분포를 보였다. 따라서 습식분쇄한 초미세액상칼슘을 분말화하여 용해성등 품질특성이 개선됨을 확인하였으며 습식분쇄기술과 분무건조법을 식품가공기술로 활용할 수 있는 가능성을 확보하였다.

A Tuber Lectin from Arisaema jacquemontii Blume with Anti-insect and Anti-proliferative Properties

  • Kaur, Manpreet;Singh, Kuljinder;Rup, Pushpinder Jai;Kamboj, Sukhdev Singh;Saxena, Ajit Kumar;Sharma, Madhunika;Bhagat, Madhulika;Sood, Sarvesh Kumar;Singh, Jatinder
    • BMB Reports
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    • 제39권4호
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    • pp.432-440
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    • 2006
  • A tuber lectin from Arisaema jacquemontii Blume belonging to family Araceae was purified by employing a single step affinity chromatography using column of asialofetuin-linked amino activated silica beads and the bound lectin was eluted with 100 mM glycine-HCl buffer pH 2.5. The purified A. jacquemontii lectin (AJL) showed a single protein band with an apparent molecular mass of 13.4 kDa when submitted to SDS-polyacrylamide gel electrophoresis under reducing as well as non-reducing conditions. The native molecular mass of AJL determined by gel filtration on a Biogel P-200 column was 52 kDa and its carbohydrate content was estimated to be 3.40%. Thus AJL is a tetrameric glycoprotein. The purified lectin agglutinated erythrocytes from rabbit but not from human. Its activity was not inhibited by any of the mono- and disaccharides tested except N-acetyl-D-lactosamine having minimal inhibitory sugar concentration (MIC) 25 mM. Among the glycoproteins tested only asialofetuin was found to be inhibitory (MIC $125\;{\mu}g/mL$). A single band was obtained in native PAGE at pH 4.5 while PAGE at pH 8.3 showed two bands. Isoelectric focusing of AJL gave multiple bands in the pI range of 4.6-5.5. When incorporated in artificial diet AJL significantly affected the development of Bactrocera cucurbitae (Coquillett) larvae indicating the possibility of using this lectin in a biotechnological strategy for insect management of cucurbits. Larvae fed on artificial diet containing sub-lethal dose of AJL showed a significant decrease in acid phosphatase and alkaline phosphatase activity while esterase activity markedly increased as compared to larvae fed on diet without lectin. Out of various human cancer cell lines employed in sulphorhodamine B (SRB) assay, this lectin was found to have appreciable inhibitory effect on the in vitro proliferation of HCT-15, HOP-62, SW-620, HT-29, IMR-32, SKOV-3, Colo-205, PC-3, HEP-2 and A-549 cancer cell lines by 82, 77, 73, 70, 41, 41, 37, 29, 21 and 21% respectively.

프로리포솜을 이용한 클렌부테롤의 경피흡수 제제화 (Proliposomal Clenbuterol Patch for Transdermal Delivery)

  • 이영주;정석재;이민화;심창구
    • Journal of Pharmaceutical Investigation
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    • 제27권4호
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    • pp.303-311
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    • 1997
  • Proliposomal patch of clenbuterol, ${\beta}_2-agonist$ bronchodilator, was prepared and its feasibility as a novel transdermal drug delivery system was examined. Proliposomal granules containing clenbuterol was prepared by a standard method using sorbitol and lecithin with (Rx 2) or without cholesterol (Rx 1). The porous structure of sorbitol in the proliposomes was maintained allowing tree flowability of the granules. Following contact with water, the granules were converted probably to liposomes almost completely within several minutes. It indicates that proliposomes may be hydrated, when they are applied on the skin under occlusive condition in vivo, by the sweat to form liposomes. Clenbuterol release from Rx 1 and Rx 2 proliposomes to pH 7.4 isotonic phospate buffer (PBS) across cellulose membrane (mol. wt. cut-off of 12000-14000) was retarded significantly compared with that from the mixture of clenbuterol powder and blank proliposomes. Interestingly, proliposomes prepared with lecithin and cholesterol (i.e., Rx 2 proliposomes) showed much more retarded release of clenbuterol than proliposomes prepared only with lecithin (i.e.. Rx 1 proliposomes), indicating that clenbuterol release from proliposomes can be controlled by the addition of cholesterol to the proliposomes. Proliposomal patches were prepared using PVC film as an occlusive backing sheet, two sides adhesive tape (urethane, 1.45 mm thickness) as a reservoir for proliposome granules and Millipore MF-membrane (0.45 mm pore size) as a drug release-controlling membrane. Rx 1 or Rx 2 proliposomes containing 4.6 mg of clenbuterol were loaded into the reservoir of the patch. Clenbuterol release from the patches to pH 7.4 PBS was determined using USP paddle (50 rpm)-over-disc release method. Clenbuterol release from the proliposomal patches was much more retarded even than from a matrix type clenbuterol patch (Boehringer Ingelheim ltd). Being consistent with clenbuterol release from the proliposomal granules, the release from the patches was highly dependent on the presence of cholesterol in the proliposomes : Patches containing Rx 2 proliposomes showed several fold slower drug release than patches containing Rx 1 proliposomes. When the patch containing Rx 1 proliposomes was applied on to the back of a hair-removed rat, clenbuterol concentration in the rat blood was maintained during 6-72 hrs. Transdermal absorption of clenbuterol from the patch was accelerated when the patch was prehydrated with 50 ml of pH 7.4 PBS before topical application. Above results indicate that sustained transdermal delivery of clenbuterol is feasible using proliposomal patches if the cholesterol content and pore size of the release rate-controlling membrane of patches, for example, are appropriately controlled.

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생사 품위향상을 위한 기초조사 연구 견층 Sericin과 용체 단백질의 용해거동에 관한 연구(III) (A Study on Basic Investigation for Quality Improvement of Raw-Silk A Study on the Dissolving Behavior of Sericin in the Cocoon Shell and Pupa Protein (Bombyx mori L.) (Part III))

  • 임영우
    • 한국잠사곤충학회지
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    • 제17권2호
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    • pp.161-170
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    • 1975
  • This study is to investigate the content of crude protein intruded in the sericin of cocoon shell and pupa by treatment of buffer solution (pH 1 to pH 13) 20 ml per 1 gram for 30 and 60 minutes at 30$^{\circ}C$, 60$^{\circ}C$ and 100${\pm}$2$^{\circ}C$, respectively. The results obtained are summarized as follows. 1. The quantity of total crude protein obtained from cocoon shell and pupa by treatment during 30 minutes at 30$^{\circ}C$ was dissolved as the largest quantity of 11.874 mg/g at pH 1 and l5.93mg/g at pH 13, but dissolved the smallest quantity 1.75g/g at pH 5 as known. and tile quantity of crude protein treated for 60 minutes is 13.437mg/g at pH 1 and 22.50mg/g at pH 13. Also, the smallest quantity is 2. 813mg/g at pH 5 as known. 2. By the treatment during 30 minutes at 60$^{\circ}C$, the dissolved largest quantity was 13.12mg/g at pH 1 and 21.875 mg/g at pH 13, but the smallest quantity is 2.375mg/g at pH 5 as known After treatment for 60 minutes at 60$^{\circ}C$, the dissolved largest quantity was 17.500 mg/g at pH 1 and 31.56mg/g at pH 13, bu the smallest quantity is 3.849 mg/g at pH 5. 3. The dissolved crude protein from the cocoon shell and pupa by treatment for 30 minutes at 100${\pm}$2$^{\circ}C$ was the largest quantity of 147.000mg/g at pH 1 and 398. 125mg/g at pH 13, but the smallest quantity is 75.00mg/g at pH 5 as known. After treatment for 60 minutes at 100${\pm}$2$^{\circ}C$, the largest quantity was 253.76 mg/g at pH 1 and 460.625mg/g at pH 13, but the smallest quantity is 139.375mg/g at pH 5 as known. 4. The dissolved crude protein from the cocoon shell and pupa was not different in quantity by treatment at 30$^{\circ}C$ or 60$^{\circ}C$. But dissolved crude protein was large quantity from cocoon shell more than pupa, as known. 5. The treatment of cocoon shell and pupa during 60 minutes at 100${\pm}$20$^{\circ}C$ was increased to the dissolved largest quantity of crude protein of 19.20% at pH 1 and 22. 18% at pH 13 from the cocoon shell and 6. 12% at pH, an d 23.87% at pH 13 from the pupa. But dissolved crude protein was increased to the larger quantity from pupa more than cocoon shell.

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Simultaneous Determination of B Group Vitamins in Supplemented Food Products by High Performance Liquid Chromatography-Diode Array Detection

  • Suh, Joon-Hyuk;Yang, Dong-Hyug;Lee, Byung-Kyu;Eom, Han-Young;Kim, Un-Yong;Kim, Jung-Hyun;Lee, Hye-Yeon;Han, Sang-Beom
    • Bulletin of the Korean Chemical Society
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    • 제32권8호
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    • pp.2648-2656
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    • 2011
  • A simple HPLC-DAD method was developed and validated to determine B group vitamin content (thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxine and folic acid) in supplemented food samples, i.e., infant formula, cereal, low-calorie food, a multi-vitamin pill and a vitamin drink. In this study, the most significant advantages were simultaneous determination of the six B group vitamins in various food matrices and a small number of sample treatment steps that required only an organic solvent, acetonitrile. Moreover, this method prevents reduction of column durability, because the mobile phase does not contain ion-pairing reagents. Analytes were separated on a Develosil RPAQUEOUS $C_{30}$ (4.6 mm ${\times}$ 250 mm, 5 ${\mu}M$ particle size) column with a gradient elution of acetonitrile and 20 mM phosphate buffer (pH 3.0) at a flow rate between 0.8 and 1.0 mL/min. Detection was performed at 275 nm, except for that of pantothenic acid (205 nm). The calibration curves for all six vitamins showed good linearity with correlation coefficients ($r^2$) higher than 0.995. The developed method was validated with respect to linearity, intra- and inter-day accuracy and precision, limit of quantification (LOQ), recovery and stability. The method showed good precision and accuracy, with intra- and inter-assay coefficients of variation less than 15% at all concentrations. The recovery was carried out according to the standard addition procedure, with yields ranging from 89.8 to 104.4%. This method was successfully applied to the determination of vitamin B groups in supplemented food products.

답전윤환형태별(畓田輪換形態別) 토양화학성(土壤化學性)과 수도생산성(水稻生産性) 변화(變化)에 관(關)한 연구(硏究) (Effect of Paddy-upland Rotation System on Soil Chemical Properties and Rice Yield)

  • 안상배;본송휘구
    • 한국토양비료학회지
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    • 제26권3호
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    • pp.181-188
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    • 1993
  • 석천미사질(石泉微砂質) 양토(壤土)에서 윤환형태(輪換形態) 및 작부체계(作付體系)에 따른 연차간(年次間) 토양질소(土壤窒素)의 무기화(無機化) 양상(樣相), 토양중(土壤中) 유기물(有機物) 및 인산(燐酸)의 변동(變動) 및 수도수량(水稻收量)과 무기성분(無機成分) 흡수량(吸收量)과의 관계를 검토(檢討)한 몇가지 결과(結果)를 요약(要約)하면 다음과 같다. 1. 긍온담수(恆溫湛水) 토양(土壤)에서 '90~'93년(年) 4년간(年間)의 4주(週) 및 10주(週)째의 질소무기화량(窒素無機化量)과 가급태(可給態) 질소함량(窒素含量)은 수도연작구(水稻連作區)보다 매년윤환구(每年輪換區) 및 2연윤환구(年輪換區)에서, 대두구(大豆區)보다 감자-배추구(區)에서 많았다. 2. 토양(土壤)중 유기물함량(有機物含量) 및 유효인산(有效燐酸)의 연차간(年次間) 변동(變動)은 수도연작구(水稻連作區)에서는 큰 변동이 없었으나 윤환구간(輪換區間)에서는 전전환구(田轉換區)>2연윤환구(年輪換區)>매년윤환구(每年輪換區)의 순(順)으로 감소되었으며 작물(作物)간에는 감자-배추구(區)보다 대두구(大豆區)에서 감소폭(減少幅)이 컸다. 3. 정조수량(正租收量)은 수도연작구(水稻連作區)에 비하여 감자-배추구(區) 및 대두구(大豆區)에서 3개년(個年) 동안 26~20%, 17~5%, 5~4% 증수(增收)되었는데 윤환년수(輪換年數)가 길수록 수량증수율(收量增收率)이 적었다. 4. 3년간(年間)('90~92년)의 수확기(收穫期) 수도(水稻) 식물체(植物體)중 모든 무기성분(無機成分) 흡수량(吸收量)은 수도(水稻) 연작구(連作區)보다 매년(每年) 윤환구(輪換區) 및 2년윤환구(年輪換區)에서, 대두구(大豆區)보다 감자-배추구(區)에서 흡수량(吸收量)이 현저히 증가되었다.

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우유의 k-Casein에서 분해된 Glycomacropeptide에 관한 연구; II. Trichloroacetic Acid의 농도에 따른 k-Casein Macropeptide 분별 특성의 변화 (Glycomacropeptide Hydrolysed from Bovine K-Casein ; II. Chromatographic Changes of k-Casein Macropetide as Related to Trichloroacetic Acid Concentration)

  • 문용일;이원재;오세종
    • 한국축산식품학회지
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    • 제25권4호
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    • pp.478-482
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    • 2005
  • k-Casein을 정제한 후 여기에 chymosin을 반응시켜 얻어진 k-Casein macropeptide에 대한 trichloroacetic acid 처리에 대한 영향을 조사하고자 ion exchange column으로 분별하여 chromatogram을 비교하였다. P-I의 경우 $3\%$ TCA에서는 전체 peak면적 대비 $46.64\%$이었으나, $6\%$$12\%$ TCA로 영향을 크게 받아 많이 침전되었으며, 상대적으로 당 함량이 높은 peak들은 TCA의 영향을 비교적 적게 받는 것으로 나타났다. Cholera 독소와 결합하는 것으로 보고된 P-III는 $3\%$ TCA에서는 $10.2\%$이었으나 $6\%$ TCA 경우에는 $26.3\%$로 상대적 면적이 증가하였으나 $12\%$ TCA로 처리한 경우에는 $13.2\%$로 감소하였다. $0.2\~0.3M$의 NaCl에서 용출되는 peak는 $12\%$ TCA에서도 상당한 안정성을 보였다. 0.18M의 NaCl gradient에서 용출되는 P-III는 $6\%$$12\%$ TCA처리시에도 cholera 독소와 반응하는 것으로 나타났다.

Characteristics of Crude Polysaccharide Separated from the Herbal Medium of Trichloloma Matsutake Mycelium and its Anti-diabetic Effect

  • Kim, Hae-Ja;Lee, Ki-Nam
    • 동의생리병리학회지
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    • 제22권3호
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    • pp.684-691
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    • 2008
  • As part of studies to develop new materials to lower blood glucose levels using crude polysaccharide, this study was attempted to analyze the characteristics of crude polysaccharide obtained from the extracts of a mixed herbal medium(OCM) where Trichloloma matsutake mycelium and Cordyceps militaris mycelium were cultured together and to look into the influence of administering these by concentration upon the blood glucose and serum lipid levels of rats with diabetes which was induced by STZ(Streptozotosin). Experimental group was divided into 6 groups: first, it was divided into normal control group(NC group) and diabetes-induced group, and diabetes-induced group was subdivided into diabetic control group(DC group), acarbose-treated group(PC group), 100 mg/kg/body weight-treated by crude polysaccharide of OCM(UE) group(UE100 group), 200 mg/kg/body weight-treated group(UE200 group), and 300 mg/kg/body weight-treated group(UE300 group). In diabetic-induced groups, after streptozotocin was melted in 0.01M citrate buffer at 50 mg/kg/body weight, when the non-fasting blood glucose level not on an empty stomach was 300 mg/dl or more in blood collected from the tail vein, it was regarded as diabetic induction and then such diabetic-induced experimental animals were used in this experiment. The yield of crude polysaccharide obtained from OCM was found to be 0.31% and the ${\beta}$-glucan content 39.40%. As a result of analyzing NO on immune function, which is known as major physiological activity of crude polysaccharide, high NO viability was shown; when 1 mg/ml LPS was treated at 1 ug/ml, it was found to be 50.77 uM, and when LPS was treated at 10 ug/m, it was found to be 53.78 uM. Also, regarding cancer cells, cell count was decreased by about 26% in proportion to sample concentration, while for normal cells, it was a little decreased in proportion to concentration, however, cell count was maintained in the range of $81.92{\sim}98.16%$ at all concentrations. In case of blood glucose level, it was decreased in all extract-treated groups compared to DC group and in the cases of ALT and AST, they were found to be lower in extract-treated groups compared to PC group and for serum lipid, it was found to be lower in UE100 group compared to PC group. Thus this study tried to utilize these results as fundamental data for development of preventive and therapeutic agents against diabetes as well as functional foods using the crude polysaccharide of mushrooms.