• Applied Microscopy
• /
• 제42권3호
• /
• pp.142-146
• /
• 2012

Doublecortin (DCX) is a microtuble-associated protein that is required for the migration of immature neuroblasts within the chick and mammalian brain. Although it is generally thought that DCX is expressed only in the neuroblasts, some mature neurons maintain DCX expression; for example, horizontal cells in adult rat retina. In this study, we demonstrate that retinal neural progenitors in the early embryonic stage of the chick also expressed DCX, as do developing ganglion cells and horizontal cells in later stages of development. These findings raise the possibility of a role for DCX in retinal neural progenitors, before they become specialized into neuroblasts in the chick.

• Animal cells and systems
• /
• 제15권2호
• /
• pp.155-159
• /
• 2011

Doublecortin (DCX) is microtubule-associated protein and is required for neuronal migration, differentiation and plasticity. In the retina, it is highly expressed between embryonic day 18 (E18) and E20, and is poorly expressed postnatally. In this study, we investigated the expression and cellular localization of DCX in the rat retina following ischemia induced by transiently increasing the intraocular pressure. While DCX immunoreactivity in control retinas was restricted to the outer border of the inner nuclear layer, it appeared in horizontal cell somata and processes in affected retinas. Quantitative evaluation by immunoblotting confirmed that DCX expression continuously increased after ischemia-reperfusion and showed 370% of control protein levels at 4 weeks after ischemic insult. These results suggest that the DCX in horizontal cells might play a role in neurite remodeling or modulating other neurons in ischemic rat retinas.

• Journal of Acupuncture Research
• /
• 제21권3호
• /
• pp.61-81
• /
• 2004

Background and Objective : The aim of this study was to investigate the effects of acupuncture and electroacupuncture on the DCX, PSA-NCAM, and pCREB expression in the brain of spontaneously hypertensive rats(SHR). Materials and Methods : SHR were divided into five groups: control group, acupuncture group, 2Hz electroacupuncture(EA) group and 100Hz EA group. We evaluated the changes of the DCX, PSA-NCAM, and pCREB positive cells using immunohistochemical method. In the olfactory bulb, we investigate the optical densities of the immunoactive cells. In the dentate gyrus and the piriform cortex, we count the immunoactive cells under the $100{\times}$ visual field optical microscope. Results : 1. The optical densities of DCX-positive cells in the subependymal zone were significantly decreased in all groups, compared to the control group. 2. The counts of DCX-positive cells in the dentate gyrus were significantly increased in all groups, compared to the control group. The counts of DCX-positive cells in the piriform cortex were significantly increased in the acupuncture and 100Hz EA group, compared to the control group. 3. The optical densities of PSA-NCAM-positive cells in the subependymal zone were significantly decreased in the acupuncture and 2Hz EA group, compared to the control group. 4. The counts of PSA-NCAM-positive cells in the dentate gyrus and the piriform cortex were significantly increased in all group, compared to the control group. 5. The counts of pCREB-positive cells in the dentate gyrus were significantly increased in all groups, compared to the control group. The counts of pCREB-positive cells in the piriform cortex were significantly increased in the acupuncture and 100Hz EA group, compared to the control group. Conclusion : We conclude that acupuncture and EA may affect neuronal cell proliferation, differentiation and plasticity in the brain.

• Journal of Power Electronics
• /
• 제19권2호
• /
• pp.380-393
• /
• 2019

Traditional boost converters have difficulty realizing high efficiency and high voltage gain conversion due to 1) extremely large duty cycles, 2) high voltage and current stresses on devices, and 3) low conversion efficiency. Therefore, a function decoupling high voltage gain DC/DC converter composed of a DC transformer (DCX) and an auxiliary converter is proposed. The role of DCX is to realize fixed gain conversion with high efficiency, whereas the role of the auxiliary converter is to regulate the output voltage. In this study, different forms of combined high voltage gain converters are compared and analyzed, and a structure is selected for the function decoupling high voltage gain converter. Then, topologies and control strategies for the DCX and auxiliary converter are discussed. On the basis of the discussion, an optimal design method for circuit parameters is proposed, and design procedures for the DCX are described in detail. Finally, a 400 W experimental prototype based on the proposed optimal design method is built to verify the accuracy of the theoretical analysis. The measured maximum conversion efficiency at rated power is 95.56%.

• Journal of electromagnetic engineering and science
• /
• 제15권3호
• /
• pp.173-180
• /
• 2015

To explore the effects of radiofrequency electromagnetic field on the fate of neuronal cells, we investigated whether exposure to 915 MHz radiofrequency identification (RFID) caused morphological changes in neuronal cells in rat hippocampal dentate gyrus (DG). A reverberation chamber was used as a whole-body RFID exposure system. Rats were assigned to two groups: sham- and RFID-exposed groups. Rats in the RFID-exposed group were exposed to RFID at 4 W/kg specific absorption rate (SAR) for 8 hours daily, 5 days per week, for 2 weeks. Morphological evaluation of DG was performed using immunohistochemistry with doublecortin (DCX) as a neuronal precursor cell marker and neuronal nuclei (NeuN) as a mature neuronal cell marker. No significant morphological changes in DCX+ or NeuN+ cells in the DG of RFID-exposed rats were observed. These results suggest that RFID exposure induces no significant change in DCX+ neuronal precursor or NeuN+ neuronal cells in DG of rats.

• Journal of Acupuncture Research
• /
• 제20권2호
• /
• pp.123-134
• /
• 2003

Objective : This experimental in vitro study investigates the effects of electro acupuncture stimuli to the DCX and PSA-NCAM positive cells in the dentate gyrus of spontaneously hypertensive rats. Methods : We used immunohistochemical methods to observe the change of neuron cells, and then counts the immunoactive cells under the $100{\times}$ visual field optical microscope. Results : 1. The counts of DCX-positive cells in the dentate gyrus significantly increased in the 2Hz group versus control group. Otherwise 100Hz group did not have a significant differance. 2. The counts of PSA-NCAM-positive cells in the dentate gyrus rather decreased in the both 2Hz group and 100Hz group versus control group. Conclusions : We find out the electro acupuncture stimuli have some effects upon cerebral neuron cell in the dentate gyrus spontaneously hypertensive rats.

• 전자공학회논문지A
• /
• 제31A권9호
• /
• pp.96-103
• /
• 1994

The GaAs epilayer was grown at low temperature (LT. 250.deg. C) by molecular beam epitaxy. The properties of the LTT GaAs, before and after Rapid Thermal Annealing(RTA), were analyzed by Reflection of High Energy Electron Diffraction (RHEED), Double Crystal X-ray(DCX), Raman spectroscopy, PL and Photo-Induced Current Transient Spectroscopy (PICTS). The LT GaAs before RTA, was analyzed by RHEED and DCX, with a result of an improved surface morphology under a relatively As-rich(As/Ga ratio :28) condition, and of an increased lattics parameter of 1.1 1.7% in comparison with a GaAs substrate. However DCX and Raman spectroscopy revealed that the expanded lattics parameter and the crystallinity of LT GaAs could be recovered after RTA. On the other hand, PL spectra indicated that LT GaAs after RTA showed low optical sensitivity unlike High Temperature(HT) GaAs, and that its surface morphology and crystallinity were corresponded with those of HT GaAs. Finally PICTS spectra proved the fact that low sensitivity of LT GaAs was due to the deep level defects (Ec-0.85eV) which were strogly formed by raising RTA temperature to 750.deg. C.

• Journal of Radiation Protection and Research
• /
• 제37권3호
• /
• pp.123-128
• /
• 2012

방사선 노출은 해마 기능이상으로 인한 인지장애와 기억력 감퇴가 나타난다. 본 연구에서는 마우스에 방사선 노출(감마선 0.5 또는 2 Gy) 후 passive avoidance 및 object recognition test를 적용한 행동이상, apoptosis 측정 및 신경발생 관찰지표로서 Kiel 67 (Ki-67) 및 doublecortin (DCX)에 대한 면역염색 방법을 적용하여 diethyldithiocarbamate(DDC)의 학습기억 장애 경감효과를 관찰하였다. DDC는 방사선 조사 30분 전에 1회(체중 kg당 1,000 mg) 복강 내 주사하였다. Passive avoidance 및 object recognition test 결과, 정상대조군에 비해 방사선 단독조사군(2 Gy)에서 유의성 있는 학습기억 장애를 나타냈으며, 방사선 조사 후 12시간에 치아이랑 부위의 apoptosis 발생세포의 수가 증가하였고, Ki-67 및 DCX 양성세포의 수는 현저히 감소하였다. 방사선 노출 전 DDC 처리군에서는 유의성 있는 행동장애 완화, apoptosis 발생 감소가 관찰되었고, 평균치를 기준으로 Ki-67 및 DCX 양성세포의 수도 약간 증가하였다. DDC는 성숙마우스에서 방사선에 의한 해마 신경세포발생 및 학습기억 장애 개선효과가 있는 것으로 사료된다.

• 한국전기전자재료학회논문지
• /
• 제13권6호
• /
• pp.467-471
• /
• 2000

The thermal annealing effect of $Zn_{0.9}Cd_{0.1}$ single quantum-well structures grown by molecular beam epitaxy is investigated. As the results of before and after rapid thermal annealed samples a red shift of E1-HH1 peak by Cd interdiffusion during thermal annealing of ZnCeSe/ZnSe sample was observed. In the case of annealed sample over $450^{\circ}C$ donor and acceptor impurities related peaks were observed which seems to be due to a diffusion of Ga and As from GaAs substrate. And also interdiffusion phenomena is idenified by the results of DCX measurements and which are consisten with the PL measurements.

• BMB Reports
• /
• 제43권2호
• /
• pp.122-126
• /
• 2010

Homozygous staggerer ($RORa^{sg/sg}$) mice showed a severe ataxia caused by cerebellum degeneration. Decreased and dysfunctional Rora is a main cause of this neurologic phenotype. The phenotype of staggerer mice has been well known in cerebellum. However, there has been rarely reported about cerebrum even though of staggerer is expressed in merely cerebellum but hippocampus, thalamus, cortex, and olfactory bulb. The expressions of Ki67, doublecortin (DCX), and NeuN, which are cell proliferation, neuronal differentiation and mature neuron markers, respectively, were measured with immunohistechemistry in dentate gyrus in staggerer mice in order to uncover whether staggerer can affect the change in dentate gyrus. The immunoreactivities of DCX and NeuN were significantly reduced in the dentate gyrus of staggerer mice than normal control, while Ki67 were rarely unchanged in staggerer mice. These results suggest that staggerer mutation has an influence on the neuronal differentiation and development not only in cerebellum but also in dentate gyrus.