• 제목/요약/키워드: Substitution Degree

검색결과 185건 처리시간 0.025초

MCT 대체지방의 산화안정성 및 조리 적합성에 관한 연구 (A Study on the Oxidative Stability and Cooking Scientific Characteristics of Fat Substitute MCT)

  • 안명수;우나리야
    • 한국식생활문화학회지
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    • 제18권2호
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    • pp.181-191
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    • 2003
  • This study was carried on the oxidative stability and the real practice possibilities in cooking of fat replacer MCT. Nowadays, it was known that fats and oils had become causes for cardiac disease, obesity and cancer, so the new materials were needed for fat substitute that has less fat contents and low calories. The food industry concerned about fats and oils had been researched and developed new and various kinds of substitute fats. MCT(medium chain triglycerides) is one of the fat based fat substitutes used as fat replacers. The POV of com germ oil(CO), soybean oil(SO), shortening(ST), butter(BT), their blended oil with MCT 10-50%(w/w), and MCT were determined and oxidative stability by POV was compared MCT with those of them. MCT has shown higher oxidative stability than CO, SO, ST, BT, so oxidative stabilities in all kinds of blended oils become higher and higher by the increased substitution ratios. In case of bread, the volume of bread prepared with MCT(MCT bread) substituted for ST at 10-40% level(w/w) were increased a little comparing to that made of shortening(ST bread). But degree of gelatinization of MCT bread were a little lower than ST bread, at the substitute ratio above 40%, the degree of gelatinization were reduced greatly. These phenomena were sustained in 9 stored days. While baking losses of MCT breads were almost same as ST bread until 30% substitute ratio, and the appearances of MCT breads were similar to ST bread until 40% substitute ratio. Also rheological properties and color(Lab) of MCT breads had shown no different significantly from ST bread until 20% substitute ratio, but by the results of sensory evaluation, overall acceptance including appearance, color, flavor, taste, texture of MCT breads were recognized almost same as ST bread by panel until 40% substitute ratio. Depends on the above results, we can suggest that 30-40% of MCT will substitute for shortening in making bread in order to reduce fat and calories intake amounts.

변성 감자 전분의 노화와 팽윤력 (The retrogradation and swelling power of modified potato starches)

  • 김지태;노완섭
    • Applied Biological Chemistry
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    • 제35권5호
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    • pp.404-409
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    • 1992
  • 치환도를 달리한 hydroxypropyl화 감자전분과 acetyl화 감자전분을 제조하여 이를 원료로 제조한 starch gel에 대한 냉동 해동 안정성과 냉장저장 안정성에 대한 pH의 영향을 조사하여 각 pH에서의 치환도에 따른 노화도를 비교 검토하였으며, 또한 이들의 팽윤력에 대한 pH 및 온도의 영향을 비교 검토하였다. 노화도는 냉장저장한 gel보다는 냉동 해동을 반복한 gel의 노화도가 더 큰 값을 나타내었으며, pH4>6>8>10의 순서로 노화도가 감소하였다. 치환도가 커질수록 노화도는 감소하였는데 천연 감자 전분보다는 ace1화 감자전분이, acetyl화 감자전분보다는 hydroxypropyl화 감자전분의 노화도가 더 적은 값을 나타내었으며, 특히 hydroxypropyl화 감자전분의 경우 pH 10에서 치환도가 클수록 gel의 안정성이 더 우수하였다. 팽윤력은 pH에 의한 영향보다는 온도에 의한 영향력이 더 켰으며, 변성전분의 치환도가 증가할수록 팽윤력이 증가하였고, acetyl화 감자전분보다는 hydroxypropyl화 감자전분이 우수하였다. 또 동일한 은도에서의 팽윤력은 pH10>2>8>4>6의 순서로 감소하였다.

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이동망 착신접속료 차등의 사회후생효과 분석 (The Effects on Social Welfare of Asymmetric Regulation in Mobile Telecommunications Termination Access Charge)

  • 정충영
    • 한국정보통신학회논문지
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    • 제13권10호
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    • pp.2030-2038
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    • 2009
  • 본 논문은 이동망 착신접속료에 대한 현재의 접속료 차등규제가 사회후생에 어떠한 영향력을 주는가를 분석 한다. 브랜드 충성도가 낮은 경우 서비스 대체성 수준과 관계없이 후발사업자의 착신접속료 증가는 사회후생을 감소시킨다. 브랜드 충성도가 높은 경우 후발사업자의 접속료가 증가함에 따라 사회후생은 증가한다. 모형을 확장하여 후발사업자의 비용이 기존사업자의 비용보다 큰 경우엔 브랜드 충성도가 증가함에 따라 사회후생 증가의 폭은 비용이 동일한 것에 비해 상대적으로 적다. 그러나 대체성이 증가함에 따라 사회후생의 감소폭은 더욱더 커진다. 후발사업자의 비용이 기존사업자의 비용보다 작은 경우엔, 전체적으로 브랜드 충성도가 증가함에 따라 사회후생의 증가폭은 더욱 커진다. 그러나 대체성이 증가함에 따라 사회후생의 감소폭은 비용이 동일할 때와 비교하면 줄어든다.

분리성 통사원자의 유형별 검토 (A Study on Some Types of Separable Syntactic Atoms in Korean)

  • 이호승
    • 비교문화연구
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    • 제38권
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    • pp.433-459
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    • 2015
  • This paper aims at a better understanding of the concept of korean separable syntactic atom, of which inner parts is separable in syntax, and at examining whether or not this concept can apply to derivatives, functional complex constructions, idiomatic expressions in korean. I defined a syntactic atom as a minimum unit which is drawn directly from lexicon and then is applied to syntactic rules. And I insist that so-called 'lexical island constraint' has some problems and that the syntactic rules can be applied to inner parts of syntactic atom, if the syntactic rules is irrelevant to new syntactic atom formation. The greater part of derivatives is non-separable syntactic atoms. But the likes of '반짝거리다', '죄송스럽다', '칭얼대다' are the separable syntactic atoms. The degree of separability of them is different in the insertion of korean particles or negative adverbs and the omission of root of sytactic atom. The derivatives of 'X-적', of which roots is regular nominal roots, permit the syntactic link between roots and the syntactic combination of the root and its argument. These kinds of derivatives is separable syntactic atoms. Also the derivatives of 'bracket paradox' and 'X-답-' derivatives is separable syntactic atoms. All functional complex constructions are not separable syntactic atoms. According to the degree of grammaticalization, inner parts of some are separable, some is non-separable. Separable functional complex constructions only permit the switching of endings or Josas but not application of other syntactic rules. All idiomatic expressions which are composed of two or more syntactic atoms are separable syntactic atoms. Some of them have so strong separability to allow the insertion of syntactic atom, adverb or adnominal modification and the noun in idiomatic expression to become the head of the relative clause. And some idiomatic expressions which have weak separability only permit interrogative's substitution or form change in fraction of idiomatic expressions.

Rice as an alternative feed ingredient in swine diets

  • Kim, Sheena;Cho, Jin Ho;Kim, Hyeun Bum;Song, Minho
    • Journal of Animal Science and Technology
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    • 제63권3호
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    • pp.465-474
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    • 2021
  • It has become important to explore alternative feed ingredients to reduce feed costs, which are burdensome for livestock production. In addition, it is desirable to find efficient and functional alternative ingredients for traditional feed ingredients in pig diets, considering the stress and sensitivity of disease of pig. Rice is produced around the world like corn that is the typical energy source in pig diets. Although the nutritional quality varies depending on the degree of milling, rice, except whole grains (paddy rice), contains more starch than corn and its structure and granule size are easier to digest than corn. In addition, the fact that rice has fewer non-starch polysaccharides (NSP) and anti-nutritional factors (ANFs) is also effective in improving digestibility and various polyphenols in rice can help modulation of immune responses, which can be beneficial to the gastrointestinal environment and health of pig. Many studies have been conducted on rice focusing on things such as degree of milling, substitution rates of corn, granule size, and processing methods. Most results have shown that rice can be partially or completely used to replace corn in pig diets without negatively affecting pig growth and production. While further research should focus on the precise biological mechanisms at play, it was confirmed that the use of rice could reduce the use of antibiotics and pig removal and protect pigs from gastrointestinal diseases including diarrhea. From this point of view, rice can be evaluated as a valuable feed ingredient for swine diets.

크로마토그래피용 O-Diethylaminoethyl Chitosan의 합성; I. 단백질의 분리 (Synthesis of O-Diethylaminoethyl Chitosan for Chromatography; I. Separation of Protein)

  • 박창규;이영무;김진홍;정창남
    • 공업화학
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    • 제4권3호
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    • pp.583-590
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    • 1993
  • 키토산 유도체 중 약한 음이온 교환기를 갖는 O-Diethylaminoethyl 키토산을 제조하여, 이를 크로마토그래피의 고정상으로 이용하여 생체단백질의 하나이며 등전점이 서로 다른 알부민과 라이소자임의 분리에 응용하였다. 우선 산성 염료와 염기성 염료를 이용하여 고정상으로서의 응용 가능성을 검토하였고 용매에 의한 극성효과도 검토하였다. 이것을 토대로 하여 크로마토그래피의 분리에 미치는 제반인자를 구하였다. 용매로써는 물과 메탄을 공용매를 사용하였고 이 경우 극성값이 증가할수록 분리능이 증가하였으며 가장 좋은 분리능은 치환도가 0.23인 경우 분리도가 1.42였다.

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Carboxymethyl-chitin 제조공정의 단순화 (The Novel Synthesis of Carboxymethyl-chitin by a New Process)

  • 한상문;안병제;김용우;김용범;유국현;이승진
    • 대한화학회지
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    • 제45권4호
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    • pp.334-340
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    • 2001
  • CM-chitin은 화장품 분야에서 보습제, 유연제, 피부관리를 위한 세포활성제 및 미백제등으로 다양하게 이용되고 있는 것으로 알려져 있다. 본 연구에서는 CM-chitin제조공정을 기존의 방법에서 몇가지 절차를 배재하여 단순화 하였다. Chitin분말을 NaOH와 혼합하고 16hrs 동안 동결 및 교반을 통해 ClCH2COONa와 isopropyl alcohol혼합액을 첨가하였다. 그 결과 높은 치환도의 CM-chitin을 얻을 수 있었다.

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The road less traveled: strategies to enhance the frequency of homology-directed repair (HDR) for increased efficiency of CRISPR/Cas-mediated transgenesis

  • Devkota, Sushil
    • BMB Reports
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    • 제51권9호
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    • pp.437-443
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    • 2018
  • Non-homologous end joining (NHEJ), and to a lesser extent, the error-free pathway known as homology-directed repair (HDR) are cellular mechanisms for recovery from double-strand DNA breaks (DSB) induced by RNA-guided programmable nuclease CRISPR/Cas. Since NHEJ is equivalent to using a duck tape to stick two pieces of metals together, the outcome of this repair mechanism is prone to error. Any out-of-frame mutations or premature stop codons resulting from NHEJ repair mechanism are extremely handy for loss-of-function studies. Substitution of a mutation on the genome with the correct exogenous repair DNA requires coordination via an error-free HDR, for targeted transgenesis. However, several practical limitations exist in harnessing the potential of HDR to replace a faulty mutation for therapeutic purposes in all cell types and more so in somatic cells. In germ cells after the DSB, copying occurs from the homologous chromosome, which increases the chances of incorporation of exogenous DNA with some degree of homology into the genome compared with somatic cells where copying from the identical sister chromatid is always preferred. This review summarizes several strategies that have been implemented to increase the frequency of HDR with a focus on somatic cells. It also highlights the limitations of this technology in gene therapy and suggests specific solutions to circumvent those barriers.

Surface Modification of Cellulose Acetate using $UV/O_3$ Irradiation

  • Lee, Hae-Sung;Jeong, Yong-Kyun;Jang, Jin-Ho
    • 한국염색가공학회지
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    • 제18권5호
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    • pp.35-41
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    • 2006
  • Upon $UV/O_3$ irradiation cellulose acetate (CA) films showed modified surface properties such as increased hydrophilicity and surface roughness as well as increased dyeability to cationic dyes. UV treatment induced photoscission of acetyl groups in the main chain of CA resulting in decreased degree of substitution from 2.2 to 1.3. The slight decreases in reflectance and transmittance were caused by remarkably increased nano-scale surface roughness of the CA surface as much as 20-fold, which can destructively interfere with visible lights of wavelength lower thu 500nm. Water contact angle decreased from $54^{\circ}\;to\;14^{\circ}$ with increasing UV energy. Surface energy also increased slightly. The surface energy change was attributed to significant contribution of polar component rather than nonpolar component indicating surface photooxidation of CA film. The increased dyeability to cationic dyes in terms of both K/S and %E may be due to photochemically introduced anionic and dipolar dyeing sites on the film surfaces.

Methionine Analogue Probes Functionally Important Residues in Active Site of Methionyl-tRNA Synthetase

  • Jo, Yeong-Joon;Lee, Sang-Won;Jo, Myung-Kyun;Lee, Jee-Woo;Kang, Mee-Kyoung;Yoon, Jeong-Hyeok;Kim, Sung-Hoon
    • BMB Reports
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    • 제32권6호
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    • pp.547-553
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    • 1999
  • Aminoacyl-tRNA synthetases are essential enzymes catalyzing the attachment of specific amino acids to cognate tRNAs. In the present work, the substrate analogue L-methionine hydroxamate was used to identify functional residues located in the active site of the E. coli methionyl-tRNA synthetase (MetRS). This compound inhibited bacteria, yeast, and human MetRS activities to a similar degree, suggesting a conserved active site structure and mechanism between MetRSs of different phylogenetic domains. Mutants of the E. coli MetRS resistant to methionine hydroxamate were also isolated. These mutants contained a substitution either at T10, Y15, or Y94. These residues are highly conserved among the different MetRSs and the mutants showed decreased aminoacylation activity, suggesting their functional and structural significances. The putative roles of these residues are discussed on a structural basis.

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