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        검색결과 55

        21.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Since expressways in South Korea are toll roads, many trumpet type interchanges exist, resulting in the installation of loop ramps very frequently. While the travel speed of the main lane is designed to be 100-110 km/h, the structure of a loop ramp is different and is designed for a minimum speed of 40 km/h. In fact, most of the actual travel speeds measured on the ramp exceed the designated speed, which has been a major problem in traffic safety. In this research, a type of pavement marking speed-reduction treatment called the "Peripheral Transverse Line" is installed on expressway loop ramps in order to study the change of driving speeds after the installation. METHODS : To verify statistically the change, this speed-reduction treatment has been installed on the Chungju interchange and the Yeoju junction. The driving speeds before the installation were compared with driving speeds both one month and five monthsafter the installation. RESULTS : As a result, the reductions of the average driving speeds after the treatment were statistically significant. More specifically, the average driving speeds of the Chungju interchange were reduced by 7.1-7.7 % for its tangent road section, and the speeds decreased by 8.5-9.5 % for its curve section. Similarly, in the Yeoju junction, an average speed reduction of 2.9-4.8 % for its tangent section was measured, along with 3.9% long-term speed reduction for its curve section. CONCLUSIONS : Since the pavement marking speed-reduction treatment has been partially proven to be effective from this research, we expect to expand this treatment and re-confirm the effect from a long-term perspective in the future.
        4,000원
        22.
        2012.06 구독 인증기관·개인회원 무료
        Hematopoietic stem cells (HSCs) are the self‐renewing, multipotent progenitors that give rise to all types of mature blood cells. The hallmark properties of HSCs are the ability to balance self‐renewal versus differentiation cell fate decisions to provide sufficient primitive cells to sustain haematopoiesis, while generating more mature cells with specialized capacities. In the present experiment, we optimized the techniques for isolation and identification of hematopoietic stem cells from cow peripheral blood. The objective of this study was to optimize the more accurate methodology for separation of mononuclear cells (MNCs) from peripheral blood and identification of HSCs by using a specific cell surface marker i.e. CD34. A total 10 peripheral blood samples were collected from Holstein dairy cows from jugular vein. We used Ficoll 400 in different concentrations from 1 to 12% and Ficollpaque Plus (1.077 g/ml) at different centrifugation speed and time. After Giemsa staining, we found more than 98% recovery of monocytes with Ficollpaque Plus (1.077 g/ml). It was demonstrated that Ficollpaque Plus (1.077 g/ml) and centrifugation at 400xg for 30 min is the best method for separation of MNCs from bovine peripheral blood. Separated MNCs were immediately subjected for magnetic activated cell sorting (MACS) by using CD34 microbead kit. HSCs (CD34+ cells) recovery was 0.307% of peripheral blood. Peripheral blood MNCs and CD34+ cells were morphologically characterized by Giemsa staining. CD34+ cells were also confirmed by immunochemistry using FITC conjugated CD34 antibodies. HSCs were also confirmed by progenitor assay including burst forming unit‐erythroid (BFU‐E), colony forming cells‐ granulocyte (CFC‐G), colony forming cells‐ macrophage (CFC‐M), colony forming cells‐ granulocyte macrophage (CFU‐GM) and colony forming cells‐ granulocyte erythroid macrophage monocyte (CFCGEMM) on Methocult 4435.
        23.
        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
        25.
        2011.09 구독 인증기관 무료, 개인회원 유료
        The present study investigated the role of peripheral P2X receptors in inflammatory pain transmission in the orofacial area in rats. Experiments were carried out on male Sprague- Dawley rats weighing 220 to 280 g. Formalin (5%, 50 μL) and complete Freund's adjuvant (CFA, 25 μL) was applied subcutaneously to the vibrissa pad to produce inflammatory pain. TNP-ATP, a P2X2,2/3,4 receptor antagonist, or OX-ATP, a P2X7 receptor antagonist, was then injected subcutaneously at 20 minutes prior to formalin injection. One of the antagonists was administered subcutaneously at three days after CFA injection. The subcutaneous injection of formalin produced a biphasic nociceptive behavioral response. Subcutaneous pretreatment with TNP-ATP (80, 160 or 240 μg) significantly suppressed the number of scratches in the second phase produced by formalin injection. The subcutaneous injection of 50 μg of OX-ATP also produced significant antinociceptive effects in the second phase. Subcutaneous injections of CFA produced increases in mechanical and thermal hypersensitivity. Both TNP-ATP (480 μg) and OX-ATP (100 μg) produced an attenuation of mechanical hypersensitivity. However, no change was observed in thermal hypersensitivity after the injection of either chemical. These results suggest that the blockade of peripheral P2X receptors is a potential therapeutic approach to the onset of inflammatory pain in the orofacial area.
        4,000원
        26.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Vanadium, a dietary micronutrient, has been reported to present interesting biological and pharmacological properties, including superoxide and nitric oxide scavenging effects. Low-dose ionizing radiation (LDR) is known to damage DNA and cause apoptosis of peripheral immunocytes by producing reactive oxygen species (ROS). The aim of this study was to elucidate the capacity of immune activation of Jeju water containing vanadium on immunosuppression caused by LDR. We examined the ROS production, DNA damage, cell apoptosis and proliferation of peripheral immunocytes in irradiated mice drinking different concentrations for 90 days; V0 (vanadium 0㎍/L, control), V1 (vanadium 15~20㎍/ L) and V2 (vanadium 20∼25㎍/L). Compared to V0 control where level of ROS showed tendency to increase, the ROS production was attenuated in peripheral immunocytes of irradiated mice drinking V1 and V2. DNA damage of peripheral immunocytes triggered by LDR significantly increased in mice drinking V0 compared to non-irradiated control, whereas V1 and V2 dramatically induced remission of DNA damage. On the observation of apoptosis of peripheral immunocytes, V1 and V2 showed the potency to reduce the number of apoptotic cells. On the other hand irradiated mice drinking V0 exhibited raised number of apoptotic cells. From the results obtained, we speculated that Jeju water containing vanadium (V1 and V2) has a potential role in decreasing DNA damage and apoptosis of immune cell by inhibiting ROS production. Consistent with this, Jeju water containing vanadium (V1 and V2) exhibits a capacity to enhance cell proliferation of peripheral immunocytes, which is suppressed by LDR as shown in V0 control. Collectively, Jeju water containing vanadium reduced DNA damage and apoptosis and induced the stimulatory potential on immunocytes. These results suggest that Jeju water containing vanadium sustained immune activities under immunosuppression caused by LDR.
        4,200원
        27.
        2010.05 구독 인증기관·개인회원 무료
        An olfactory system is one of the complicatedly-equipped sensory facilities in the insect sensory systems, which is most essential for insect olfactory-driven behaviors relevant to survival such as finding hosts, mates, oviposition sites, and food resources. These behaviors are mostly controlled by circadian rhythm. The american cockroach, Periplaneta americana, has been an ideal model to extensively study olfactory system associated with complex behavioral repertoires and circadian controls of certain behaviors, respectively. Even though it is known that olfactory-related physiology in peripheral and central olfactory systems seems to be highly variable by circadian rhythms, little is known about how these are controlled at the neuronal and molecular levels. It has been reported that the plasticity in the olfactory system is modulated by a set of neuropeptides. However, it remains still elusive how these neuropeptides and neuroendocrine system interact in the peripheral systems to change olfactory responses in cockroaches. Here, current study focuses on the localization of neuropeptides and their receptors by using in situ hybridization and immunostaining methods. Also, expression level of these genes are evaulated by qRT-PCR methods. Circadian fluctuation of these genes seem to be important neurotransmission machineries in the periphery. Our current study suggests that microcircuits of neuronal systems in the peripheral olfactory organ play an important in olfactory modulation by circadian rhythm
        29.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 성별, 좌우안 및 나이에 따른 중심 및 주변부 각막두께, 각막중심부와 가장 얇은 곳의 상관관계를 분석하기 위하여 비접촉식 Scheimpflug photography를 이용하여 측정하였다. 방법: 각막질환이 없고 건강한 대학생 51명(남자 29명, 여자 22명, 평균나이 22.50±3.31세)과 장노년층 39명(남자 21명, 여자 18명, 평균 나이 54.26±6.25세) 총 180안을 대상으로 Pentacam(Oculus Co.)을 이용하여 동공중심, 동공중심에서 3 mm 떨어진 상, 하, 좌, 우 지점, 가장 얇은 곳의 각막 두께를 측정하였다. 결과: 대학생의 평균 중심각막두께는 555.98±32.69 μm, 주변부는 위쪽, 코쪽, 아래쪽, 귀쪽 순으로 681.72±36.04 μm, 653.34±38.04 μm, 628.69±35.18 μm, 624.26±36.06 μm이었고, 장노년층의 평균 중심각막두께는 543.69±33.40 μm, 주변부는 위쪽, 코쪽, 아래쪽, 귀쪽 순으로 649.97±45.53 μm, 630.95±39.65 μm, 620.94±37.09 μm, 614.28±35.59 μm이었다. 성별(t=-0.3966, p=0.69214) 및 좌우안(t=-0.41772, p=0.67665)에 따른 유의한 차이는 없었으나, 나이에 따라서는 유의한 차이가 있는 것으로 나타났으며(t=2.47572, p=0.01423), 음의 상관관계가 나타났다(각각 r=-0.414, r=-0.254, r=-0.155 and r=-0.203). 각막에서 가장 얇은 곳은 하이측에 존재하였으며(우안: r=0.69±0.25 μm, θ=209.49˚, 77/90안, 좌안: r=0.57±0.22 μm, θ=-41.57˚, 78/90안), 각막 중심두께와 가장 얇은 곳과는 유의한 차이가 나타나지 않았다(t=-1.6229, p=0.10549). 결론: 각막두께는 성별 및 좌우안에 따라서는 유의한 차이가 나타나지 않으나, 나이가 증가할수록 음의 상관관계가 나타났으며 특히 상비측이 얇아진다. 또한, 각막에서 가장 얇은 곳은 대부분 하이측에 존재하였다. 이와 같은 생리적 변화는 증가하는 굴절수술 및 안과적 수술에 유용한 정보를 제공할 수 있을 것으로 생각된다.
        4,000원
        32.
        2008.09 구독 인증기관 무료, 개인회원 유료
        The present study investigated the role of peripheral group I, II, and III metabotropic glutamate receptors (mGluRs) in mustard oil (MO)-induced nociceptive response in the masseter muscles of lightly anesthetized rats. Experiments were carried out on male Sprague-Dawley rats weighing 300-350 gm. After initial anesthesia with sodium pentobarbital (40 mg/kg, i.p.), one femoral vein was cannulated and connected to an infusion pump for intravenous infusion of sodium pentobarbital. The rate of infusion was adjusted to provide a constant level of anesthesia. MO (30 μL) was injected into the mid-region of the left masseter muscle via a 30-gauge needle over 10 seconds. After 30 mL injection of 5, 10, 15, or 20% MO into the masseter muscle, total number of hindpaw-shaking behavior was monitored. Intramuscular administration of MO significantly produced hindpawshaking behavior in a dose-dependent manner, as compared with the vehicle (mineral oil)-treated group. Intramuscular pretreatment with 10 or 100 ng DHPG, a group I mGluRs agonist, enhanced MO-induced hindpaw-shaking behavior, while APDC (20 or 200 μg), a group II mGluRs agonist, or L-AP4 (2 μg), a group III mGluRs agonist, significantly reduced MO-induced nociceptive behavior. The antinociception, produced by group II or III mGluRs agonists, was abolished by pretreatment with LY341495, a group II mGluRs antagonist, or CPPG, a group III mGluRs antagonist, res-pectively. Based on these observations, peripheral mGluRs differentially modulated MO-induced nociceptive behavior response in the craniofacial muscle pain and peripheral group II and III mGluRs agonists could be used in treatment of craniofacial muscle nociception.
        4,000원
        36.
        2003.12 구독 인증기관 무료, 개인회원 유료
        The present study were performed to analysis the hematocrit and the red blood cells content into the blood plasma of the transgenic pigs harboring recombinent human erythropoietin gene (rhEPO). Mouse whey acidic protein (mWAP) linked to rhEPO gene was microinjected into pronuclei of porcine one-cell zygotes. After delivered of offspring, PCR analyses identified one mWAP-rhEPO transgenic founder offspring(F/sub 0/). The first generation of transgenic pig (F/sub 0/) harboring mWAP-hEPO appeared to be a male, and the second generation (F₁) pigs were made by natural mating of F/sub 0/ with domestic swine, and male and female transgenic pigs (F₁) were identified by PCR. The blood samples from transgenic and normal pigs were collected for 50 days during lactation and were counted the red blood cell (RBC) numbers and Hematocrit (HCT) content into the blood. The transgenic pigs expressing rhEPO in their blood gave rise to higher RBC numbers and HCT contents than control animals. rhEPO was secreted both in the blood and milk of genetically engineered pigs harboring rhEPO gene. Therefore, this study provides a model regarding the production of transgenic pig carrying hEPO transgene for biomedical research.
        4,000원
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