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        검색결과 360

        81.
        2013.06 구독 인증기관 무료, 개인회원 유료
        A method for rapid micropropagation of Ophiopogon japonicus through plant regeneration from leaf, rhizome and root explants derived calli has been developed. Leaf, rhizome and root segments were cultured on Murashige and Skoog (MS) medium supplemented with plant growth regulators (2,4-D, NAA, IAA; 0~3.0 mg/ L) for callus induction. Callus production was highest at 1.0 mg/L 2,4-D where 91%. These calli were transferred to MS medium supplemented with various concentrations of 2,4-D (0, 0.5, 1.0, 3.0 mg/L) in combination with 6-benzyladenine (BA: 0, 0.5, 1.0 and 3.0 mg/L) for adventitious shoot regeneration. The addition of low concentration of 2,4-D into BA containing medium significantly increased the frequency of shoot regeneration in both leaf, rhizome and root derived calli. The highest frequency of adventitious shoot (88%) formation was on MS medium supplemented with 0.5 mg/L 2,4-D and 1.0 mg/L BA. For rooting of the shoots, half-strength MS medium supplemented with different concentrations of plant growth regulators (2,4-D, IBA, NAA) 0, 0.1, 1.0, 3.0 mg/L was tried. The optimal results was observed on half-strength MS medium supplemented with 3.0 mg/L NAA (average of 42.9 roots per explant). In vitro raised plantlets were acclimatized and transferred to soil with 100% success. This in vitro propagation protocol would be useful for conservation as well as mass propagation of this medical plant.
        4,000원
        82.
        2013.02 구독 인증기관 무료, 개인회원 유료
        In order to prove that perchlorate-laden resins could be bio-regenerated through direct contact with anaerobic microorganisms, two bio-regeneration systems, internal and external, were tested. Anaerobic digestion was demonstrated to be very efficient in degrading perchlorate that had been adsorbed onto A520E resin. The internal bio-regeneration test showed that the fully exhausted resins recovered about 80% of the perchlorate-exchange capacity after 4 weeks of bio-treatment in the anaerobic digester. The bio-regeneration efficiency of the external system increased with the amount of flow passed through the column. Comparison of two perchlorate breakthrough curves obtained from column test, one with virgin resin and the other with bio-regenerated resin, proved that the bio-regenerated resin could be used repeatedly to treat perchlorate in spent or waste brine. The A520E resin was very stable in the anaerobic digester and its perchlorate-exchange capacity was barely changed during 26 weeks of incubation. The most significant contribution of this research is to develop the concept of direct bio-regeneration of exhausted resins by combining physicochemical ion-exchange and biological reduction technology, especially for the removal of perchlorate.
        4,000원
        83.
        2012.12 구독 인증기관 무료, 개인회원 유료
        This experiments were carried out to find out the effects of different explant materials, kinds and concentration of plant growth regulators on the in vitro regeneration of Iris pseudoacorus L. The effects of growth regulators on regeneration from three explant sources (root, rhizome and leaf) were more or less same. Explants produced only callus with 2,4-D treatment and other regulators had no effects. The highest frequency of callus induction (rhizome: 84%) was on MS media supplemented with 1.0 mg/L 2,4-D. For plant regeneration, when calli were transferred to the first media supplemented with 1.0 mg/L BA and 1.0 mg/L 2,4- D. Regenerated plants were successfully acclimatized in soil containing a mixture of vermiculite : perlite : leafmold (1 : 1 : 1), and their survival was high.
        4,000원
        84.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Poly-L-lactic acid (PLLA), PLLA/hydroxyapatite (HA), PLLA/multiwalled carbon nanotubes (MWNTs)/HA, PLLA/trifluoroethanol (TFE), PLLA/gelatin, and carbon nanofibers (CNFs)/β-tricalcium phosphate (β-TCP) composite membranes (scaffolds) were fabricated by electrospinning and their morphologies, and mechanical properties were characterized for use in bone tissue regeneration/guided tissue regeneration. MWNTs and HA nanoparticles were well distributed in the membranes and the degradation characteristics were improved. PLLA/MWNTs/HA membranes enhanced the adhesion and proliferation of periodontal ligament cells (PDLCs) by 30% and inhibited the adhesion of gingival epithelial cells by 30%. Osteoblast-like MG-63 cells on the randomly fiber oriented PLLA/TEF membrane showed irregular forms, while the cells exhibited shuttle-like shapes on the parallel fiber oriented membrane. Classical supersaturated simulated body fluids were modified by CO2 bubbling and applied to promote the biomineralization of the PLLA/gelatin membrane; this resulted in predictions of bone bonding bioactivity of the substrates. The β-TCP membranes exhibit good biocompatibility, have an effect on PDLC growth comparable to that of pure CNF membrane, and can be applied as scaffolds for bone tissue regeneration.
        4,300원
        86.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study purposed to examine the effect of low power laser on pain response and axonal regeneration. In order to prepare peripheral nerve injury models, we crushed the sciatic nerve of Sprague-Dawley rats and treated them with low power laser for 21 days. The rats were divided into 4 groups: normal group(n=10); control group(n=10) without any treatment after the induction of sciatic nerve crush injury; experimental group I(n=10) treated with low power laser(0.21mJ/㎟) after the induction of sciatic nerve crush injury; and experimental group II(n=10) treated with low power laser(5.25mJ/㎟) after the induction of sciatic nerve crush injury. We measured spontaneous pain behavior(paw withdrawal latency test) and mechanical allodynia(von Frey filament test) for evaluating pain behavioral response, and measured the sciatic function index for evaluating the functional recovery of peripheral nerve before the induction of sciatic nerve crush injury and on day 1, 7, 14 and 21 after the induction. After the experiment was completed, changes in the H & E stain and toluidine blue stain were examined histopathologically, and changes in MAG(myelin associated glycoprotein) and c-fos were examined immunohistologically. According to the results of this study, when low power laser was applied to rat models with sciatic nerve crush injury for 21 days and the results were examined through pain behavior evaluation and neurobehavioral, histopathological and immunohistological analyses, low power laser was found to affect pain response and axonal regeneration in both experimental group I and experimental group II. Moreover, the effect on pain response and axonal regeneration was more positive in experimental group I to which output 0.21mJ/㎟ was applied than in experimental group II to which 5.25mJ/㎟ was applied.
        4,200원
        87.
        2012.03 구독 인증기관 무료, 개인회원 유료
        This study demonstrated that hyaluronic acid (HA) accelerated peripheral nerve regeneration after crush injury to the common peroneal nerve in an experimental rabbit model. Ten male New Zealand White rabbits, weighing 1.8 to 2.0 kg, were used in this study. After creating the nerve crush model in every right leg, rabbits were divided into two groups. Animals in group A received application of HA into the area surrounding the crushed nerve, and group B was the sham control. Electrophysiological assessment was performed every week. After 10 weeks, nerve histological examination, muscle weight and muscle histology were used to evaluate regeneration of the injured common peroneal nerve. No differences in electrophysiological assessment were observed between the two groups. In peripheral nerve histology, myelinated nerve fibers were observed more frequently and less connective tissue was observed in the crushed nerve of group A. Fewer muscle degenerative changes, such as fibrosis, atrophy, and centrally located myonuclei, were detected in group A than in group B. In conclusion, HA could become a potential neuroprotective agent for improvement of peripheral nerve regeneration after crush injury.
        4,000원
        88.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Endothelial cells are a vital constituent of most mammalian organs and are required to maintain the integrity of these tissues. These cells also play a major role in angiogenesis, inflammatory reactions, and in the regulation of thrombosis. Angiogenesis facilitates pulp formation and produces the vessels which are essential for the maintenance of tooth homeostasis. These vessels can also be used in bone and tissue regeneration, and in surgical procedures to place implants or to remove cancerous tissue. Furthermore, endothelial cell regeneration is the most critical component of the tooth generation process. The aim of the present study was to stimulate endothelial regeneration at a site of acute cyclophosphamide (CP)-induced endothelial injury by treatment with human umbilical cord-derived endothelial/mesenchymal stem cells (hEPCs). We randomly assigned 16 to 20-week-old female NOD/SCID mice into three separate groups, a hEPC (1 × 105 cells) transplanted, 300mg/kg CP treated and saline (control) group. The mice were sacrificed on days 5 and 10 and blood was collected via the abdominal aorta for analysis. The alanine transaminase (ALT), aspartate aminotransferase (AST), serum alkaline phosphatase (s-ALP), and albumin (ALB) levels were then evaluated. Tissue sections from the livers and kidneys were stained with hematoxylin and eosin (HE) for microscopic analysis and were subjected to immunohistochemistry to evaluate any changes in the endothelial layer. CP treatment caused a weight reduction after one day. The kidney/body weight ratio increased in the hEPC treated animals compared with the CP only group at 10 days. Moreover, hEPC treatment resulted in reduced s-ALP, AST, ALT levels compared with the CP only group at 10 days. The CP only animals further showed endothelial injuries at five days which were recovered by hEPC treatment at 10 days. The number of CD31-positive cells was increased by hEPC treatment at both 5 and 10 days. In conclusion, the CP-induced disruption of endothelial cells is recovered by hEPC treatment, indicating that hEPC transplantation has potential benefits in the treatment of endothelial damage.
        4,000원
        89.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국내 개발 재배품종인 코스피드 이탈리안 라이그라스의 최적 배양조건을 확립하기 위하여 성숙종자로부터 캘러스 유도조건 및 식물체 재분화 조건을 조사하였다. 캘러스 유도시 첨가되는 auxin으로는 2,4-D가 NAA 보다 효율적이었으며, 5 mg/L 2,4-D가 첨가된 N6 배지에서 캘러스가 가장 높은 빈도로 유도되었다. 캘러스로부터 식물체 재분화는 1 mg/L 2,4-D와 5mg/L BA가 첨가된 N6 배지에서 배양했을 때 67% 이상의 재분화율을 나타내었
        4,000원
        90.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        갈대의 성숙종자로부터 최적 조직배양조건을 확립하기 위하여 종자로부터 캘러스 유도 및 식물체 재분화 체계를 확립하였다. 종자로부터 캘러스 유도시 첨가되는 auxin으로는 2,4-D가 가장 효율적이었으며, 1.0 mg/L 2,4-D와 0.5 mg/L BA가 첨가된 MS 배지에서 가장 높은 빈도로 캘러스가 유도되었다. 캘러스로부터 식물체 재분화는 cytokinin류인 BA와 kinetin이 첨가되지 않은 MS 배지에서 59.6%로 높은 재분화 효율을 나타내었
        4,000원
        91.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        버뮤다그라스는 현재 난지형 목초자원으로 많이 이용되고 있을 뿐만 아니라, 잔디용으로도 많이 이용되고 있는 품종 중의 하나이다. 그러나 난지형 목초인 버뮤다그라스는 동절기의 동해를 받아 일부 고사하거나 생육이 불량하며, 여름철 병해충 등의 발생으로 유지 관리가 어려운 단점이 있다. 따라서 버뮤다그라스의 이러한 문제점을 개선하기 위해서는 동해와 같은 각종 환경 스트레스에 잘 견디는 신품종개발이 시급한 실정이다. 본 연구에서는 버뮤다그라스의 성숙종자로부터 생
        4,000원
        92.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Siberian wildrye grass는 몽골지역 방목 초지에 넓게 분포하는 대표적인 초종으로 사료가치가 높고 장기간 이용 할 수 있는 장점 등으로 그 중요성이 증대되고 있다. 그러나 최근 기후 변화로 인한 사막화로 초지의 면적이 점점 줄어들고 있는 추세이다. 따라서 환경에 대한 적응성이 우수한 신품종을 개발할 목적으로 우선 효율적인 기내배양 조건을 확립하고자 하였다. Siberian wildrye grass의 최적의 기내배양 조건을 확립하기 위하여
        4,000원
        93.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        티모시의 4가지 품종을 이용하여 성숙종자로 부터 캘러스 유도 및 식물체 재분화 효율을 조사하였다. 4주 동안 배양한 종자로부터 캘러스 유도율은 Colt, Chair, Richmond, Hokuo 순으로 캘러스 유도율을 보였고, 식물체로의 재분화 또한 캘러스 유도율과 같은 Colt > Chair > Richmond > Hokuo 순으로 나타났다. 기본 배지의 종류에 따른 배양 효율의 차이는 품종별 차이는 있으나 MS 배지가, 식물체 재분화는 N6 배지와
        4,000원
        94.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The forest of Korea had been severely degraded since early 1900s until 1950s. Korean Government has successfully accomplished the reforestation works since 1960s. However, some plantations showed poor survival and growth caused by ignoring site characteristics in selecting plantation species and lack of tending works such as thinning. The natural regeneration of indigenous species, such as Quercus species and Pinus densiflora Siebold & Zucc., were examined in the plantations of Pinus koraiensis Siebold & Zucc. and Larix kaempferi Fortune ex Gordon. Quercus species regenerated mainly by sprouting while P. densiflora regenerated naturally from a few mother trees that remained in the plantations. P. koraiensis showed poor survival (IVI ≤ 25%) and suppressed growth (height ≤ 3 m and DBH ≤ 3 cm at 20 year-old) by Quercus species or P. densiflora in the plantation areas, however had high survival (IVI ≥70%) and growth (8 m height and 14.1 cm DBH at 20 year-old) in areas where silvicultural practices were conducted. L. kaempferi showed good survival (IVI ≥40%) and growth (17.2 m height and 16.3 cm DBH at 30 year-old) mostly in valley areas, while it was nearly dead (IVI ≤ 10%) in ridge or ridge-slope areas and was replaced by indigenous species such as Quercus species (IVI ≥ 25~55%) or P. densiflora (IVI ≥ 18~50%).
        4,300원
        95.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Peripheral nerve injuries are very common in clinics and often result in severe functional deficits. The aim of this study was to evaluate the effect of treadmill running and electro-acupuncture on nerve regeneration and functional recovery of muscle activity following sciatic nerve crush injury in a rat model. A comparative study was conducted over 30 days on 60 adult male Sprague-Dawley rats grouped into sham control (C), electro-acupuncture (EA), treadmill (T), and treadmill plus electro-acupuncture (TEA). The left sciatic nerve was crushed for 30 sec using a hemostatic forceps and functional activity was evaluated with sciatic functional tests, nerve conduct velocity, muscle weight, and histology at 10, 20, and 30 days after injury. Muscle weight was significantly (P<0.05) increased between days 10 and 30 in the TEA group. In histology, the degree of damage was scored as C > TEA > T > EA, although necrosis and fibrosis of muscle was observed only in the TEA group. The EA and TEA groups showed rapid recovery with better myelinated axons on day 10. These results suggest that application of the TEA method with balanced exercise is a useful treatment option for peripheral nerve injury regeneration and muscle activity.
        4,000원
        96.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        단풍나무류의 활력있는 종자의 공급량을 파악해 보고자, 2009년과 2010년의 초가을에 단풍속 6수종, 복장나무, 고로쇠나무, 우산고로쇠, 부게꽃나무, 당단풍 및 단풍나무 종자를 채취하여 종자특성과 종자활력을 조사하였다. 화서형태는 복장나무, 당단풍과 단풍나무는 산방화서(corymb), 고로쇠나무와 우산고로쇠는 위가 편평한 원추화서(flat-topped panicle), 부게꽃나무는 총상화서(raceme)였다. 화서당 종자?V의 개수는 부게꽃나무가 38.5개로 가장 많았고, 당단풍이 2.4개로 가장 적었다. 종자직경은 우산고로쇠가 13.5mm로 가장 크고, 당단풍이 4.7mm로 가장 작았다. 시과의 각도는 당단풍이 130.05˚로 가장 크고, 부게꽃나무가 48.60˚로 가장 작았다. 20 시과?V의 건조중량은 우산고로쇠가 3,900mg으로 가장 무거웠고, 부게꽃나무가 404mg으로 가장 가벼웠다. 채종한 단풍나무류 종자의 건전종자의 비율은 단풍나무는 50%, 다음으로 부게꽃나무는 43.2%로 나타났다. 나머지 4 수종은 8.6~22.2% 정도로 나타나, 낙하종자에 대한 설치류의 피식량, 건조의 피해, 낙엽층의 발아방해 등을 고려하면 고로쇠, 우산고로쇠 복장나무, 당단풍나무 등의 천연갱신이 잘 이루어지지 않는 것이 건전종자의 공급량 부족이 하나의 원인일 수 있을 것이라 사료된다. 고로쇠, 우산고로쇠, 부게꽃나무 및 당단풍나무의 종피에서 벌레에 의한 천공피해가 관찰되었으며, 고로쇠나무와 우산고로쇠의 종자에서는 검정긴꽃바구미(Bradybatus sharpi)가 공통적으로 관찰되었다. 단풍나무류의 천연갱신을 이해하기 위해서 종자결실과 비산전 후 종자피식 문제에 대한 장기간의 연구가 필요할 것이라 사료된다.
        4,000원
        97.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzed on the characteristics of temperature distribution in an active regeneration DPF using computer simulation. In order to verify the boundary condition of analysis, results of temperature distribution in DPF are compared between experimental and computer simulation. Using this boundary condition, temperature distribution and filter's durability in DPF analyzed according to various operating conditions. The results of computational analysis are agreed well with experimental ones from the tendency of temperature distribution of axis and radius direction. The temperature increases and the axial temperature gradients in DPF according to velocity of exhaust gas are lowered as the high velocity of exhaust gas. But the temperature gradients of radius direction at exit side in DPF are grown as the high velocity of exhaust gas. The results according to inlet temperature of exhaust gas show that the increase ratios of temperature in DPF are grown as the high temperature of exhaust gas.
        4,000원
        100.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        기니아그라스의 유성생식 계통과 아포믹시스 계통을 이용하여 최적의 조직배양 조건을 검토하기 위하여 절편체 부위의 조직배양 능력 및 배양배지의 조건을 검토하였다. 그 결과 미성 숙배를 분리한 후 L-proline 2 g/L가 첨가된 캘러스 유도 배지에 치상하였을 때 높은 캘러스 유도율 및 활발한 증식을 관찰할 수 있었다. 또한 유도된 캘러스를 대상으로 재분화 효율을 조사한 결과, 성숙종자 유래의 캘러스는 재분화 능력을 가지고 있지 않은 반면에, 미성숙배 유
        4,000원
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