Brain Topological Correlates of Motor Performance Changes After Repetitive Transcranial Magnetic Stimulation

Park, Chang-hyun,Chang, Won Hyuk,Yoo, Woo-Kyoung,Shin, Yong-Il,Kim, Sung Tae,Kim, Yun-Hee Mary Ann Liebert 2014 Brain connectivity Vol.4 No.4

<P>Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain networks and specifically the association of brain topological changes with motor performance changes. In a sham-controlled parallel group experimental design, real or sham rTMS was administered to each of the 15 healthy subjects without prior motor-related dysfunctions, over the right M1 at a high frequency of 10 Hz. Before and after the intervention, fMRI data were acquired during a sequential finger motor task using the left, nondominant hand. Changes in the topology of brain networks were assessed in terms of global and local efficiency, which measures the efficiency in transporting information at global and local scales, respectively, provided by graph-theoretical analysis. Greater motor performance changes toward improvements after real rTMS were shown in individuals who exhibited more increases in global efficiency and more decreases in local efficiency. The enhancement of motor performance after rTMS is supposed to be associated with brain topological changes, such that global information exchange is facilitated, while local information exchange is restricted.</P>

Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER)

Cho, Yong-Chan,Lee, Chang-Seok,Cho, Hyun-Je,Lee, Kyu-Song,Park, Pil-Sun The Ecological Society of Korea 2011 Journal of Ecology and Environment Vol.34 No.1

Various responses of forest ecosystems to climate change underscore the need to improve our understanding of the environmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetation dynamics based on changes in community structure, species composition, diversity and demographics in four Korean National Long Term Ecological Research (KNLTER) sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri--between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was not observed in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitude gradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Work showed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes of species richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas one species disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order): Mt. Nam (25.5%), Mt. Jeombong (24.3%), Mt. Worak (16.4%) and Mt. Jiri (0.8%). In the pine forest, the recruitment rate was as follows (in descending order): Mt. Nam (63.7%), Mt. Worak (12.9%), Mt. Jeombong (7.6%) and Mt. Jiri (7.3%). The mortality rate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002), and the recruitment rate and change rate of density were positively correlated (r = 0.77, P = 0.026). In the KNLTER sites, larger vegetation changes were attributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affect these changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.

Long second toe: its nail and skin changes

( Geun-hwi Park ),( Woo-il Kim ),( Min-young Yang ),( Won-ku Lee ),( Tae-wook Kim ),( Sung-min Park ),( Hyun-joo Lee ),( Gun-wook Kim ),( Hoon-soo Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Nail can be affected by trauma, infection, and systematic disorders. In particular, the toe nails are exposed to the repeated and cumulative minor traumas, which usually result in thickened, splitted, and discolorated nails. Considering these, it can be inferred that the long second toe can be related to various nail and skin changes by repeated minor traumas such as friction in shoes, but the study or report on this topic hasn’t been done yet. Objectives: The purpose of this study was to introduce various nail and skin changes on long second toe. Methods: We analyzed the kinds of nail/skin changes of 50 patients with long second toe, enrolled at Pusan National University Hospitals (Busan and Yangsan) from 2013 to 2018. Results: There was no significant difference in the incidence of left and right toe and toenail, and 7 (14%) patients presented bilateral distribution. The most common nail change on long second toe was melanonychia (23, 46%), followed by subungual hematoma (15, 30%), onycholysis (2, 4%), subungual hyperkeratosis (2, 4%), onychomadesis (1, 2%), and retronychia (1, 2%). The most common skin change was corn (9, 18%), followed by paronychia (2, 4%). Twenty (20/50, 40%) patients also had other toe or toenail changes. Among them, the most common site was big toe/nail (13, 62%), and the most common change was subungual hematoma (8, 42%). Conclusion: Through this study, the dermatologists can recognize and diagnose the nail and skin changes of long second toe.

Analysis of Genetic Diversity of Korean Wheat Cultivars Using Microsatellite DNA Polymorphisms

Park,Yong-Jin,Cho,Gyu-Taek,Ma,Kyung-Ho,Lee,Sok-Young,Lee,Jung-Ro,Kim,Young-Chang,Cho,Eun-Gi,Kim Chang-Yung,Nam,Jung-Hyun,Rao,V,Ramanatha,Kang,Hee-Kyoung 한국자원식물학회 2004 Plant Resources Vol.7 No.2

Genetic background and phylogenetic relationships among 20 Korean wheat cultivars were assessed using microsatellites after amplifying with 13 SSR primer pairs. Average allele number per primer pair was 3.36. Genetic similarities for every pair of cultivars ranged from 0.42 to 0.97, with 0.69 of overall average. Korean cultivars were divided into two major groups based on microsatellite DNA polymorphisms. Group I consisted of relatively old cultivars developed until 1970s, and group II contained the recent cultivars developed during 1980s and 1990s. Amongst old elite cultivars/lines, ‘Yukseung 3’, ‘Norin 12’ and ‘Norin 72’ contributed most to the genetic background of cultivars belonging to group I, and ‘Norin 4’, ‘Norin 12’, ‘Norin 43’ and ‘Norin 72’ to group II, respectively. The phylogenetic relationship of Korean wheat cultivars was in accordance with the genealogical data of each cultivar. The genetic background of each cultivar was assessed from the point of breeding and germplasm management such as variety identification and duplicated accessions for assisting in developing a system for the registration of new variety based on the molecular characterization in future.

흰쥐에서 분리 배양한 척수앞뿔신경세포의 형태 분화 및 축삭 형성

엄창섭,엄창섭,박창현,권계숙,유임주,박선화,전용혁 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.2

Cytochalasin B와 Colchicine이 생쥐 간장의 담세관과 간세포의 미세구조에 미치는 영향

박창현,장병준,엄창섭,엄창섭 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.2

VARIATION OF 24-HOUR INTRAOCULAR PRESSURE IN SILICONE OIL–FILLED EYES

Chang, Joo Hyun,Shin, Jae Pil,Kim, In Taek,Park, Dong Ho Lippincott 2016 Retina Vol.36 No.1

<P>Purpose:To evaluate the variation of 24-hour intraocular pressure (IOP) in silicone oil (SO)-filled eyes.Methods:Prospective, nonrandomized comparative case series of 42 eyes of 21 patients, each with an SO-filled eye after vitrectomy. The fellow eyes served as controls. Each subject slept the usual 8 hours, and IOPs were measured at 4-hour intervals over 24 hours, twice before sleep (5:30 and 9:30 pm), twice during sleep (1:30 and 5:30 am), and twice after sleep (9.30 am and 1:30 pm). Intraocular pressure was measured in the sitting position using a Goldmann applanation tonometer. The SO-filled eyes and fellow eyes were compared with respect to diurnal-to-nocturnal and nocturnal-to-diurnal IOP changes.Results:At all 6 time points, SO-filled eyes had higher mean IOPs than fellow eyes (all P < 0.05). For both groups, mean nocturnal IOP was higher than mean diurnal IOP (both P < 0.001). Changes in diurnal-to-nocturnal IOP and nocturnal-to-diurnal IOP between SO-filled eyes and fellow eyes did not differ significantly (P > 0.05, respectively). The peak IOP occurred in the nocturnal period for all fellow eyes and for 94.7% of SO-filled eyes.Conclusion:The IOP of SO-filled eyes varied over a 24-hour period, peaking largely in the nocturnal period, as observed for the IOP of fellow eyes.</P>

Numerical analysis of flow and bed change at a confluence of the Namhan River and the Seom River using a two-dimensional model

Park Moonhyung,Kim Hyung Suk,Baek Chang Hyun 한국수자원학회 2018 한국수자원학회논문집 Vol.51 No.12

본 연구에서는 4대강 살리기 사업 후 퇴적현상이 지배적으로 발생하는 남한강과 섬강 합류부 구간을 대상으로 2차원 수치모형인 CCHE2D 모형을 이용하여 하천의 흐름 및 하상변동에 대한 해석을 수행하였다. 대상지점 합류부는 남한강 본류의 만곡부에 지류 섬강이 유입되는 특성을 갖는다. CCHE2D 모형은 비평형 유사이송을 해석하며 소류사와 부유사 조정거리가 중요한 입력변수로 대상지점에서는 소류사 조정거리가 하상변동에 가장 큰 영향을 주는 것으로 나타났다. 수치모의 결과 유량비(Qr) 변화가 남한강과 섬강 합류부 지점에서 흐름 및 하상변동에 영향을 미쳤으며, Qr≤ 2.5인 경우에는 합류전 본류의 유속이 증가하여 흐름박리구역을 감소시켰으며 이로 인해 합류부 내측의 퇴적이 감소하였다. Qr>2.5이면 합류부 구간에 퇴적이 증가하여 사주가 형성될 가능성이 높은 것으로 나타났다. 수치모의를 통해 2013년에 발생한 유량비 변화에 의해 합류부에 고정사 주가 형성된 것을 알 수 있었다. The flow and bed change were analyzed using the CCHE2D model, which is a two-dimensional numerical model, at a confluence of the Namhan River and Seom River where deposition occurs predominantly after the “Four Major Rivers Restoration Project.” The characteristic of the junction is that the tributary of Seom River joined into the curved channel of the main reach of the Namhan River. The CCHE2D model analyzes the non-equilibrium sediment transport, and the adaptation lengths for the bed load and suspended load are important variables in the model. At the target area, the adaptation length for the bed load showed the greatest influence on the river bed change. Numerical simulation results demonstrated that the discharge ratio (Qr) change affected the flow and bed change in the Namhan River and Seom river junction. When Qr ≤2.5, the flow velocity of the main reach increased before confluence, thereby reducing the flow separation zone and decreasing the deposition inside the junction. When Qr>2.5, there was a high possibility that deposition would be increased, thereby forming sand bar. Numerical simulation showed that a fixed sand bar has been formed at the junction due to the change of discharge ratio, which occurred in 2013.

Bone Marrow T Cells are Superior to Splenic T Cells to Induce Chimeric Conversion After Non-Myeloablative Bone Marrow Transplantation

( Hyun Sil Park ),( Seok Goo Cho ),( Min Jung Park ),( So Youn Min ),( Hong Seok Chang ),( Hee Je Kim ),( Seok Lee ),( Chang Ki Min ),( Jong Wook Lee ),( Woo Sung Min ),( Chun Choo Kim ),( Ho Youn Kim 대한내과학회 2009 The Korean Journal of Internal Medicine Vol.24 No.3

Background/Aims: The bone marrow functions not only as the primary B-lymphocyte-producing organ but also as a secondary lymphoid organ for CD4 and CD8 cell responses and a site of preferential homing and persistence for memory T cells. Bone marrow T (BM-T) cells are distinguished from peripheral blood T cells by surface phenotype, cytokine secretion profile, and immune functions. In this study, we evaluated the alloreactive potential of donor lymphocyte infusion (DLI) using BM-T cells in mixed chimerism compared to that using spleen T (SP-T) cells. Methods: Cells were prepared using established procedures. BM-T cells were obtained as a by-product of T-cell depletion in BM grafting and then cryopreserved for subsequent DLI. We performed DLI using BM-T cells in allogeneic mixed chimera mice on post-BMT day 21. Results: When the same dose of T cells, 5-10×105 (Thy1.2+), fractionated from BM and spleen were administered into mixed chimeras, the BM-T group showed complete chimeric conversion, with self-limited graftversus-host disease (GVHD) and no pathological changes. However, the SP-T group showed persistent mixed chimerism, with pathological signs of GVHD in the liver and intestine. Conclusions: Our results suggest that DLI using BM-T cells, even in small numbers, is more potent at inducing chimeric conversion in mixed chimerism than DLI using SP-T cells. Further study is needed to determine whether cryopreserved BM-T cells are an effective cell source for DLI to consolidate donor-dominant chimerism in clinical practice without concerns about GVHD. (Korean J Intern Med 2009;24:252-262)

A New MPEG-2 Rate Control Scheme Using Scene Change Detection

Park, Sang-Gyu,Lee, Young-Sun,Chang, Hyun-Sik Electronics and Telecommunications Research Instit 1996 ETRI Journal Vol.18 No.2

We propose two new rate control schemes to improve MPEG-2 rate control in view of visual quality when scene changes happen. Two proposed schemes are characterized by real-time and non real-time improvement to reduce the impact of scene changes. We also propose a new target-bit prediction method using spatial activity of pictures and present a simple and efficient scene change detection scheme using signed difference of mean absolute difference (MAD). Computer simulation results show that the proposed real-time algorithm effectively alleviates visual quality degradation after scene changes. The proposed non real-time algorithm gives maximum 2 dB improvement in peak signal-to-noise ratio (PSNR) at a scene-changed picture, compared with MPEG-2 rate control scheme and it shows better quality than the real-time one.