• Title/Summary/Keyword: Frozen

Search Result 2,678, Processing Time 0.027 seconds

Comparison of Vitrification and Slow Freezing for the Cryopreservation of Mouse Pronuclear Stage Embryos (생쥐 전핵기 배아 냉동보존에서 완만동결과 유리화동결의 비교)

  • Kim, Mi-Young;Lee, Yu-Il
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.34 no.2
    • /
    • pp.117-124
    • /
    • 2007
  • Objective: The aim of this study was to compare the efficacy of slow freezing with vitrification method for cryopreservation of mouse pronuclear stage embryos. Methods: Mouse pronuclear embryos obtained from superovulated mice and classified into 2 groups of slow freezing and vitrification. Slow freezing solution consisted of 1.5 M PROH, 0.1 M sucrose, while vitrification solution consisted of 40% ethylene glycol, 18% Ficoll and 0.5 M sucrose diluted in Dulbecco's phosphate-buffered saline supplemented with 10% SSS. Recovery and survival rates after thawing and development rates to hatching balstocyst stage were compared between two groups. Results: After freezing and thawing, recovery rate of slow freezing group was 93.8%, whereas vitrification group was 66.5% (p<0.01). Survival rate of recovered embryos were similar between two groups as 83.2% in slow freezing and 87.6% in vitrification. Embryo development rates to 2-cell stage after 24 hrs (77.0% vs 59.1%), 4-cell after 48 hrs (72.6% vs 53.3%), blastocyst after 96 hrs (53.1% vs 40.1%) of thawing were significantly higher in vitrification group than those of slow freezing group, respectively. Conclusion: The vitrification method may provide better developmental competence of frozen-thawed embryos than that of slow freezing method for cryopreservation of mouse pronuclear stage embryos.

Changes of Characteristics in Red Pepper by Various Freezing and Thawing Methods (홍고추의 저장온도 및 해동조건에 따른 물리화학적 특성 변화)

  • Lee, Hye-Eun;Lim, Chai-Il;Do, Kyung-Ran
    • Food Science and Preservation
    • /
    • v.14 no.3
    • /
    • pp.227-232
    • /
    • 2007
  • The development of an effective long-term storage protocol for harvested fresh pepper is urgently required to increase the market for pepper products. The protocol must minimize quality loss, so that the product may be used either as a spice or as a raw material for processed pepper products, both in the home and in food processing plants. We investigated the optimum size of pepper fruits, freezing temperatures, storage periods, and thawing methods, to establish an optimum storage protocol. This study was conducted not only to develop freezing and thawing methods for long term storage of harvested red pepper, but also to develop processed pepper products utilizing the stored pepper. We aimed to expand the pepper products market and to increase the incomes of pepper growers. Whole red pepper, sliced red pepper, and crushed red pepper were frozen and stored at $-5^{\circ}C,\;-20^{\circ}C,\;or\;-40^{\circ}C$. The soluble solid content and the vitamin C level showed maximal stability at $-40^{\circ}C$, although total free sugars decreased on storage at all temperatures tested. Such Changes were more marked at $-5^{\circ}C$ than at the other(lower) temperature tested. The vitamin C content of whole red pepper was higher than that of sliced red pepper or crushed red pepper. Room-temperature thawing resulted in twice the drip loss seen on low temperature($5^{\circ}C$) thawing or microwave oven thawing. Brown discoloration was a serious problem with room temperature thawing. Total free sugars were higher in samples thawed at low temperature or in the microwave oven, compared to the level seen after room-temperature thawing. pepper samples thawed at low temperature scored higher in sensory tests than samples thawed at room temperature.

Quality characteristics of steamed rice cake with Schisandra chinensis powder or extract added prior to storage (오미자 분말 및 추출물 첨가 설기떡의 저장 중 품질특성)

  • Kim, Dae-Hyun;Cho, Jeong-Seok;Park, Jung-Hoon;Kim, Jae-Hwan;Moon, Kwang-Deog
    • Food Science and Preservation
    • /
    • v.23 no.7
    • /
    • pp.923-930
    • /
    • 2016
  • The purpose of this study was to improve the quality of the steamed rice cakes added with powder and extract of Schisandra chinensis (SC). Steamed rice cakes were prepared by adding SC using 1% hot-air dried SC powder (DP), hot-air dried SC extract (DE), freeze dried SC powder (FP) and, frozen SC extract (FE). After packaging with nylon/polyethylene films, the cakes were stored at $25^{\circ}C$ for 5 days. The FE-treated steamed rice cake had the lowest pH value. The $L^*$ value of the control cakes was highest immediately after processing and decreased during storage. The $a^*$ values of FP- and FE-treated steamed rice cakes were higher than those of DP- and DE-treated cakes. The $b^*$ values of DP- and DE-treated steamed rice cakes were higher than those of FP- and FE-treated cakes. Total phenolic contents of DP and DE were lower than those of FP and FE. Anthocyanin contents of DP- and DE-treated steamed rice cakes were lower than those of FP- and FE-treated cakes. Schisandrin contents of DP- and FP-treated steamed rice cakes were lower than those of DE- and FE-treated cakes. Ferric reducing antioxidant power assays revealed that DP and DE had lower antioxidant powers than those of FP and FE. The results of this study indicate that, among the treatments methods used, the steamed rice cake treated with FE had the highest functional component and antioxidant activity levels.

Studies on the Lipid Components of Potato Tubers - I. Lipid Composition in Free and Bound Lipids - (감자의 지방질(脂肪質) 성분(成分)에 관한 연구(硏究) - 제(第) 1보(報) : 유리(遊離) 및 결합(結合) 지질(脂質)중의 지방질(脂肪質) 조성(組成)에 관하여 -)

  • Lee, Sang-Young;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
    • /
    • v.11 no.4
    • /
    • pp.291-297
    • /
    • 1979
  • The experimentally cultivated potatoes of 4 varieties, Irish Cobbler, Warba, Shimabara, and Saco were dried in a frozen state, powdered subsequently and subjected to the extraction of free and bound lipids. Constituents of the prepared lipids were fractionated, quantified, and compared by the methods of column and gas-liquid chromatographies. The results were summarized as follows : 1. The total crude lipid content in potato on a dry weight basis was 0.57 % of which 0.2 % was free lipid and 0.37 % was bound lipid. 2. The neutral lipid content in the free lipid was 14.9 %, approximately 3 times as much as the 4.5 % contained in the bound lipid, whereas the glycolipid content in the free lipid was 15.1 %, slightly less than 22.2 % contained in the bound lipid. However, the phospholipid content was 33.9 % in the bound lipid, approximately 4.5 times as much as the 7.2 % contained in the free lipid. This fact revealed that the bound lipid consisted mainly of polar lipid, while the free lipid consisted of neutral lipids, glycolipids and phospholipids in about the same proportion. 3. The main fatty acids constituting more than 90 % in the free and bound lipids were linoleic, palmitic and linolenic acids. The content of the saturated fatty acid was slightly less in the free lipid than in the bound lipid, whereas the unsaturated fatty acids were more abundant in the free lipid.

  • PDF

Localization of the Neurons Projecting to the Gallbladder Meridian (족소양담경(足少陽膽經)에서 투사(投射)되는 신경원(神經元)의 표지부위(標識部位)에 대한 연구(硏究))

  • Ryuk Sang-Won;Lee Kwang-Gyu;Lee Sang-Ryoung;Kim Jum-Young;Lee Chang-Hyun;Lee Bong-Hee
    • Korean Journal of Acupuncture
    • /
    • v.17 no.1
    • /
    • pp.101-121
    • /
    • 2000
  • The purpose of this morphological studies was to investigate the relation to the meridian, acupoint and nerve. The common locations of the spinal cord and brain projecting to the the gallbladder, GB34 and common peroneal nerve were observed following injection of transsynaptic neurotropic virus, pseudorabies virus(PRV), into the gallbladder, GB34 and common peroneal nerve of the rabbit. After survival times of 96 hours following injection of PRV, the thirty rabbits were perfused, and their spinal cord and brain were frozen sectioned($30{\mu}m$). These sections were stained by PRV immunohistochemical staining method, and observed with light microscope. The results were as follows: 1. In spinal cord, PRV labeled neurons projecting to the gallbladder, GB34 and common peroneal nerve were founded in thoracic, lumbar and sacral spinal segments. Densely labeled areas of each spinal cord segment were founded in lamina V, VII, X, intermediolateral nucleus and dorsal nucleus. 2. In medulla oblongata, The PRV labeled neurons projecting to the gallbladder, GB34 and common peroneal nerve were founded in the A1 noradrenalin cells/C1 adrenalin cells/caudoventrolateral reticular nucleus, rostroventrolateral reticular nucleus, medullary reticular nucleus, dorsal motor nucleus of vagus nerve, nucleus tractus solitarius, raphe obscurus nucleus, raphe pallidus nucleus, raphe magnus nucleus, gigantocellular nucleus, lateral paragigantocellular nucleus, principal sensory trigeminal nucleus and spinal trigeminal nucleus. 3. In Pons, PRV labeled neurons were parabrachial nucleus, Kolliker-Fuse nucleus and cochlear nucleus. 4. In midbrain, PRV labeled neurons were founded in central gray matter and substantia nigra. 5. In diencephalon, PRV labeled neurons were founded in lateral hypothalamic nucleus, suprachiasmatic nucleus and paraventricular hypothalamic nucleus. 6. In cerebral cortex, PRV labeled neuron were founded in hind limb area.This results suggest that PRV labeled common areas of the spinal cord projecting to the gallbladder, GB34 and common peroneal nerve may be first-order neurons related to the somatic sensory, viscero-somatic sensory and symapathetic preganglionic neurons, and PRV labeled common area of the brain may be first, second and third-order neurons response to the movement of smooth muscle in gallbladder and blood vessels.These PRV labeled neurons may be central autonomic center related to the integration and modulation of reflex control linked to the sensory system monitoring the internal environment, including both visceral sensation and various chemical and physical qualities of the bloodstream. The present morphological results provide that gallbladder meridian and acupoint may be related to the central autonomic pathways.

  • PDF

A Study on the Correlation between Categorization of the Individual Exposure Levels to Agent Orange and Serum Dioxin Levels Among the Korean Vietnam Veterans (베트남 참전 제대 군인의 범주화된 에이전트 오렌지 개인 폭로량과 혈청 다이옥신 측정치와의 상관성에 관한 연구)

  • Kang, Han-K.;Lim, Hyun-Sul;Cheong, Hae-Kwan;Lim, Min-Kyung;Kim, Joung-Soon
    • Journal of Preventive Medicine and Public Health
    • /
    • v.34 no.1
    • /
    • pp.80-88
    • /
    • 2001
  • Objectives : In an epidemiologic study on the health impact of Agent Orange exposure, the valid estimation of exposure level is the most important step. Based on recent studies, we examined the correlation between exposure levels categorized by personal exposure estimates and serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD, Dioxin), exploring the possibility of utilizing the exposure level as a surrogate for the estimate of exposure to agent orange. Methods : During the study period (Jan 1996-Feb 1996), blood specimens of 745 subjects taken randomly among 1,329 persons and kept frozen, were analyzed for 2,3,7,8-TCDO and six other dioxin congeners. The serum dioxin and congeners were measured in 1998 by CDC, adjusted for serum lipids. We categorized the total exposure scores into five groups based on Agent Orange exposure data collected by interview and military records. Pearson and Spearman's correlation coefficients & multiple regression analysis were used to identify the relationship of the exposure level categorized with serum concentration of 2,3,7,8-TCDD, and six other dioxin congeners. Results : Dioxin and the other congeners, except 1,2,4,6,7,8-HpCDD, showed significant correlations to exposure categories (p<0.005): 2,3,7,8-TCDD and OCDD showed positive correlations, whereas the other congeners did negative. The values of 2,3,7,8-TCDD differed according to exposure category and proportionally increased from the low exposure group to the high, a dose-response relationship, even after other possible confounding variables were adjusted for. In multiple regression analysis, age$(\beta=0.033)$, dioxin$(\beta=0.433)$, 1,2,3,7,8-PeCDD$(\beta=-0.998)$, 1,2,3,4,7,8-HxCDD$(\beta=-0.773)$, 1,2,3,6,7,8-HxCDD$(\beta=0.255)$, 1,2,3,7,8,9-HxCDD$(\beta=-3.468)$, 1,2,3,4,6,7,8-HpCDD$(\beta=0.109)$ we re found to be significantly related to the total exposure score(p<0.005). Conclusion : This study demonstrated that the use of such categorizations as a surrogate measure of agent orange exposure in identifying exposure degrees in a health impact study is valid.

  • PDF

Observation, Experiment, and Analysis of the Ice Spikes Formation (솟는 고드름의 형성과정에 관한 관찰, 실험 및 분석)

  • Yoon, Ma-Byong;Kim, Hee-Soo;Son, Jeong-Ho;Yang, Jeong-Woo
    • Journal of the Korean earth science society
    • /
    • v.30 no.4
    • /
    • pp.454-463
    • /
    • 2009
  • In this study, from January 2006 to February 2009, we observed 107 ice spikes formed in a natural state, and analyzed their environment. We developed an experimental device to reproduce ice spikes in laboratory and successfully made 531 ice spikes. We analyzed the process of the formation and the principle of how those ice spikes grow through videotaped data of the formation in the experiment. In the natural world, when the surface of water and the lower part of a vessel begin to freeze, a vent (breathing hole) develops at the surface where an ice is not frozen; this vent serves as the seed of an ice spike. It is assumed that the volume expansion of ice in the vessel which occurs when water freezes makes the supercooled water go upward through the vent and becomes an ice bar called an ice spike. In the laboratory, however, when distilled water is poured into an ice tray cube and kept in the experimental device for about one and a half hours at a temperature of -12- $-13^{\circ}C$, a thin layer of ice then begins to develop on the surface of the water, the vent is formed, and ice spikes form for about 10-30 minutes. These spikes stop growing when the end becomes clogged. Ice spikes can be described as falling into seven categories of shape, with the apex type topping the list followed by the slant type in the natural state and the vertical type predominating in the laboratory.

Effect of Feeding of Citrus Byproducts on Physicochemical and Sensory Characteristics of Chicken Meat (감귤부산물 급여가 닭고기의 이화학적 특성 및 관능적 특성에 미치는 영향)

  • Moon, Yoon-Hee;Jung, In-Chul
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.38 no.6
    • /
    • pp.766-772
    • /
    • 2009
  • In this study, the effects of feeding citrus byproduct on physicochemical and sensory characteristics of chicken meats were investigated. The samples consisted of chicken meats provided with only feed for laying hen without citrus byproduct (T-0), and the chicken meats fed with 1.0%, 1.5% and 2.0% citrus byproduct during the starter (initial period feed; $1{\sim}9th$ day), the grower (middle period feed; $10{\sim}24th$ day), and the finisher (latter period feed; $25{\sim}36th$ day), respectively. The $L^*$ value of thigh was significantly lower in the T-1 than in the T-0, the $a^*$ value was significantly higher in the T-1 than in the T-0 (p<0.05). The water holding capacity of thigh was significantly higher in the T-1 than in the T-0 and the cooking loss was significantly higher in the T-0 than in the T-1 (p<0.05). The acid value was significantly higher in the T-0 than in the T-1 (p<0.05). Antioxidant activity was higher in the T1 than in the T-0 (p<0.05). There was no significance between T-0 and T-1 regardless of feeding citrus byproduct, in terms of chicken's $b^*$ value, frozen loss, thawing loss, hardness, springiness, cohesiveness, gumminess, chewiness, shear force, free amino acid content of hot water extracts, taste, flavor, tenderness, juiciness and palatability.

Volatile Flavor Compounds of Korean Native Lilium (한국 자생나리의 휘발성 향기성분)

  • Choi Sung-Hee;Im Sungim;Jang Eun-Young;Kim Kiu-Weon
    • Journal of Life Science
    • /
    • v.15 no.4 s.71
    • /
    • pp.548-552
    • /
    • 2005
  • Volatile fragrance components in 5 kinds of Korean native Lilium were investigated and compared. The volatile components were extracted by SDE (simultaneous steam distillation and extraction) and identified by CC and GC-MS. As a result of the analysis of volatile aromatic ingredient of L. leichtlinii var. tigrinum Nickels., L. concolor var. parthneion Bak., L. tsingtauense Gilg., L. hansonii Leichtl., and L. amabile Palibin., using frozen materials, 60 kinds of volatile compound were identified, which were 28 aldehydes, 9 ketones, 8 alcohols, 5 esters, 5 acids, 3 furans and 2 others. The GC patterns of the aroma components of all samples resembled but the peak areas were different according to species, though all of them are Korean native Liliums.

THREE-DIMENSIONAL PHOTOELATIC STRESS ANALYSIS OF CLASP RETAINERS INFLUENCED BY VARIOUS DESIGNS ON UNILATERAL FREE-END REMOVABLE PARTIAL DENTURES (하악 편측 유리단 국소의치의 직접유지장치 형태에 따른 3차원적 광탄성 응력분석 연구)

  • Kim Byeong-Moo;Yoo Kwang-Hee
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.32 no.4
    • /
    • pp.526-552
    • /
    • 1994
  • The extent and direction of movement of removable partial dentures during function are influenced by the nature of the supporting structures and and the design of the prosthesis. Since forces are transmitted to the abutment teeth through occlusal rests, guide planes and direct retainers during functional movements, proper design based on the avaialble research data will maintain the health of abutment teeth and their supporting structures. The purpose of this in vitro study is evaluating stress distribution clinically around the abutment teeth prepared following 4-type clasping systems for unilateral free-end removable partial dentures. Three-Dimensional Photoelastic Stress Analysis method was used because it shows a visual display of stresses of the simulated abutment teeth and residual ridges and reveals stress concentration that can be read at any given points in terms of direction and magnitude. For this study, the author fabricated 4 mandibular photoelastic epoxy models missing left 1st and End molar. Epoxy models were duplicated and 4 unilateral removable partial dentures were construe- ted in accordance with 4-type direct retainers. Unilateral free-end removable partial dentures were positioned on their own models. 6kg force was loaded on the every removable partial dentures of the epoxy model on the central fossa of mandibular left 1st molar vertically by the loading device. After the stress was frozen in a stress freezing furnace, 6 specimens of 6-mm thickness were made from every epoxy model and examined with the circular polariscope. The results were as follows : 1. Generally I-bar clasp revealed the most favorable stress distribution around the abutment teeth. 2. At the end portion of the free-end ridge, Back action clasp showed the highest stress concentration at the bucco-lingual and top portions of the residual alveolar ridge. 3. At the distal area of the abutment teeth, Akers clasp and Roach clasp showed higher stress concentration bucco-lingually and apically than the others. 4. To the abutment tooth, I-bar clasp showed the least stress distribution bucco-lingually but the others showed irregular stress distribution. 5. At the mesial area of the abutment teeth, the order of effective stress distribution was I-bar clasp, Back-action clasp, Akers clasp and Roach clasp. There was big difference of stress distribution between them. 6. At the right 2nd premolar and 1st molar, the stress concentration of Akers clasp was a little high but that of I-bar clasp was low.

  • PDF