Plate Fixation for Atypical Fractures of the Femoral Diaphysis

Youngho Cho,Young-Soo Byun,Seongwoo Jo,Jaeuk Shin 대한정형외과학회 2022 Clinics in Orthopedic Surgery Vol.14 No.2

Background: Plate fixation for atypical femoral fractures has shown high failure rates compared to intramedullary nail fixation. The aim of this study was to evaluate the radiological results of patients treated with a plate and screws for atypical fractures of the femoral diaphysis. Methods: This study was conducted retrospectively on 16 patients who had undergone internal fixation using plates for treatment of atypical femoral complete fractures from 2007 to 2015. Nine patients were treated with lag screws and short plates while 7 patients were treated with position screws and long plates, which covered the whole femur. Radiologic evaluation was performed on all patients. Complications were also evaluated. Results: Bone union was achieved in all patients and the average bone union time was 17.7 weeks (range, 14–28 weeks). There was no correlation between the preoperative use of a bisphosphonate, plate length, postoperative teriparatide use, and the time to bone union. Regarding complications, 2 cases of complete fractures and 1 impending fracture occurred at the end of short plates. Conclusions: Satisfactory results were obtained with use of plates for patients with atypical femoral complete diaphyseal fractures, in whom intramedullary nails could not be applied due to severe bowing. In particular, it seemed advantageous compared with intramedullary nail fixation in that it could maintain the leg length through anatomical reduction and prevent iatrogenic fracture.

Hyperspectral depth-profiling with deep Raman spectroscopy for detecting chemicals in building materials

Cho, Youngho,Song, Si Won,Sung, Jiha,Jeong, Young-Su,Park, Chan Ryang,Kim, Hyung Min Royal Society of Chemistry 2017 The Analyst Vol.142 No.19

<P>Toxic chemicals inside building materials have long-term harmful effects on human bodies. To prevent secondary damage caused by the evaporation of latent chemicals, it is necessary to detect the chemicals inside building materials at an early stage. Deep Raman spectroscopy is a potential candidate for on-site detection because it can provide molecular information about subsurface components. However, it is very difficult to spectrally distinguish the Raman signal of the internal chemicals from the background signal of the surrounding materials and to acquire the geometric information of chemicals. In this study, we developed hyperspectral wide-depth spatially offset Raman spectroscopy coupled with a data processing algorithm to identify toxic chemicals, such as chemical warfare agent (CWA) simulants in building materials. Furthermore, the spatial distribution of the chemicals and the thickness of the building material were also measured from one-dimensional (1D) spectral variation.</P>

Changes in Biston robustum and Camellia japonica distributions, according to climate change predictions in South Korea

Youngho Cho,Tae Guen Kim,한용구,Youngjin Kim,Ohseok KWON 한국생태학회 2015 Journal of Ecology and Environment Vol.38 No.3

We investigated the current and potential spatial distributions and habitable areas of Biston robustum and Camellia japonica in South Korea in order to provide useful data for the conservation of C. japonica and minimize the damage caused by B. robustum. It was predicted that, by 2070, although B. robustum would be widely distributed throughout the Korean Peninsula, except for the western and eastern coastal areas, it would be narrowly distributed along the Sokcho-si and Goseong-gun coastlines in Gangwon Province. C. japonica is currently located along the southern coastline but its critical habitable area is predicted to gradually disappear by 2070. Assessment of the potential distribution probabilities of B. robustum and C. japonica revealed that the area under the curve (AUC) values were 0.995 and 0.991, respectively, which indicate high precision and applicability of the model. Major factors influencing the potential distribution of B. robustum included precipitation of wettest quarter and annual precipitation (BIO16 and BIO12), whereas annual mean temperature and mean temperature of wettest quarter (BIO1 and BIO8) were important variables for explaining C. japonica distribution. Overlapping areas of B. robustum and C. japonica were 11,782 km2, 5447 km2, and 870 km2 for the current, 2050-predicted, and 2070-predicted conditions, respectively, clearly showing a dramatic decrease in area. Although it is predicted that B. robustum would cause continuous damage to C. japonica in the southern part of the Korean Peninsula, such impacts might diminish over time and become negligible in the future.

Phenotypic Characterization of Peripheral T Cells and Their Dynamics in Scrub Typhus Patients

Cho, Bon-A,Ko, Youngho,Kim, Yeon-Sook,Kim, Sanguk,Choi, Myung-Sik,Kim, Ik-Sang,Kim, Hang-Rae,Cho, Nam-Hyuk Public Library of Science 2012 PLoS neglected tropical diseases Vol.6 No.8

<▼1><P><B>Background</B></P><P>Scrub typhus, caused by <I>Orientia tsutsugamushi</I> infection, is one of the main causes of febrile illness in the Asia-Pacific region. Although cell-mediated immunity plays an important role in protection, little is known about the phenotypic changes and dynamics of leukocytes in scrub typhus patients.</P><P><B>Methodology/Principal Findings</B></P><P>To reveal the underlying mechanisms of immunological pathogenesis, we extensively analyzed peripheral blood leukocytes, especially T cells, during acute and convalescent phases of infection in human patients and compared with healthy volunteers. We observed neutrophilia and CD4<SUP>+</SUP> T lymphopenia in the acute phase of infection, followed by proliferation of CD8<SUP>+</SUP> T cells during the convalescent phase. Massive T cell apoptosis was detected in the acute phase and preferential increase of CD8<SUP>+</SUP> T cells with activated phenotypes was observed in both acute and convalescent phases, which might be associated or correlated with elevated serum IL-7 and IL-15. Interestingly, peripheral Treg cells were significantly down-regulated throughout the disease course.</P><P><B>Conclusions/Significance</B></P><P>The remarkable decrease of CD4<SUP>+</SUP> T cells, including Treg cells, during the acute phase of infection may contribute to the loss of immunological memory that are often observed in vaccine studies and recurrent human infection.</P></▼1><▼2><P><B>Author Summary</B></P><P>Scrub typhus is an acute febrile illness caused by <I>Orientia tsutsugamushi</I> infection. It has been estimated that one billion people are at risk and one million new cases arise each year in Asian-pacific region. Despite of aggressive attempts to develop a prophylactic vaccine against scrub typhus during the last several decades, all approaches have failed to generate long lasting immunity. In addition, little is known about the immunological pathogenesis of scrub typhus. To understand the pathogenic mechanisms of this infectious disease, we extensively analyzed peripheral leukocytes, especially T cells, in Korean scrub typhus patients and compared with healthy volunteers. We observed neutrophilia and CD4<SUP>+</SUP>/T lymphopenia in the acute phase of infection, followed by proliferation of CD8<SUP>+</SUP> T cells during the convalescent phase. Massive T cell apoptosis was detected in the acute phase and a preferential increase of CD8<SUP>+</SUP> T cells with activated phenotypes was observed in both acute and convalescent phases. The remarkable decrease of CD4<SUP>+</SUP> T cells, including Treg cells, during the acute phase of infection may contribute to the loss of immunological memory and generate helpless but unregulated cytotoxic T cell responses observed in vaccine studies and recurrent human infection.</P></▼2>

Genetic Relationships between Mt. Halla and Mongolian Populations of Hipparchia autonoe (Lepidoptera: Nymphalidae)

Youngho Cho,Jeong Sun Park,Min Jee Kim,Deuk-Soo Choi,Sang-Ho Nam,Iksoo Kim 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.04

Hipparchia autonoe belongs to the family Nymphalidae (Lepidoptera) and is designated as an endangered insect and national monument in Korea. It only inhabits a very restricted area on Mt. Halla but is widely distributed in several Asian countries including Mongolia. A previous study conducted to understand the genetic relationship between Mt. Halla and Mongolian H. autonoe for conservation purposes suffered from a limited number of samples. Therefore, we sequenced the DNA barcode region of an additional 36 H. autonoe individuals, combined them with previous data from 19 individuals, and performed phylogenetic and population genetic analyses. Furthermore, the internal transcribed spacer 2 (ITS2) region was also sequenced from the 36 samples as a nuclear DNA marker. The existence of independent haplotypes, sequence types, and significant FST estimates (p < 0.05) between Mt. Halla and Mongolian populations indicated hampered gene flow between the populations. Nevertheless, an absence of a reciprocal monophyletic group in Mt. Halla and Mongolian populations by cytochrome oxidase subunit I gene- and ITS2-based phylogeny suggests that the genetic isolation of the Mt. Halla population from the Mongolian populations seemed not large enough to consider them independent genetic entities.

Broadband supercontinuum generation using a hollow optical fiber filled with copper-ion-modified DNA

Cho, Youngho,Park, Byeongho,Oh, Juyeong,Seo, Minah,Lee, Kwanil,Kim, Chulki,Lee, Taikjin,Woo, Deok Ha,Lee, Seok,Kim, Hyung Min,Lee, HyukJae,Oh, Kyunghwan,Yeom, Dong-Il,Dugasani, Sreekantha Reddy,Park, The Optical Society 2015 Optics express Vol.23 No.10

Osteoperiosteal Decortication and Autogenous Cancellous Bone Graft Combined with Bridge Plating for Non-hypertrophic Diaphyseal Nonunion

Youngho Cho,Young-Soo Byun,Jeong-Duk Suh,Junhyug Yoo 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.3

Background: The aim of this study was to evaluate results of osteoperiosteal decortication and autogenous cancellous bone graft combined with a bridge plating technique in atrophic and oligotrophic femoral and tibial diaphyseal nonunion. Methods: We retrospectively reviewed 31 patients with atrophic or oligotrophic femoral and tibial diaphyseal nonunion treated with osteoperiosteal decortication and autogenous cancellous bone graft between January 2008 and December 2018. Patients with hypertrophic nonunion, infected nonunion, and nonunion treated with autogenous cancellous bone graft alone were excluded. The nonunion site was exposed by using the Judet technique of osteoperiosteal decortication. Nonunion with a lack of stability was stabilized with a new plate using a bridge plating technique or augmented by supplemental fixation with a plate. Nonunion with malalignment was stabilized with a new plate after deformity correction. Autogenous cancellous bone graft was harvested from the posterior iliac crest and placed within the area of decortication. A basic demographic survey was conducted, and the type of existing implants, mechanical stability of the implants, the type of implants used for stabilization, the operation time, the time to bone union, and postoperative complications were investigated. Results: The average follow-up period was 33.3 months (range, 8–108 months). The operation time was 207 minutes (range, 100– 351 minutes). All but 1 nonunion (96.7%) were healed at an average of 4.2 months (range, 3–8 months). In 1 patient, bone union failed due to implant loosening with absorbed bone graft, and solid union was achieved by an additional surgery for stable fixation with a new plate, osteoperiosteal decortication, and autogenous cancellous bone graft. There were no other major complications such as neurovascular injuries, infection, loss of fixation, and malunion. Conclusions: Osteoperiosteal decortication and autogenous cancellous bone graft combined with stable fixation by bridge plating showed reliable outcomes in atrophic and oligotrophic diaphyseal nonunion. This treatment modality can be effective for treating atrophic and oligotrophic diaphyseal nonunion because it is very helpful stimulating bone union.

Indoor Accelerated Complex Test of PV Module

YoungHo Cho(조영호),YongHyun Cho(조용현),GyuGwang Kim(김규광),YeonBae Shin(신연배),Donggun Lim(임동건) 한국태양에너지학회 2023 한국태양에너지학회 학술대회논문집 Vol.2023 No.4

Electoral Competitiveness and Perceived Election Quality: Unraveling the Mediational Role of District-level Turnout in the 2016 Korean Legislative Election

Youngho Cho(조영호),Beomseob Park(박범섭) 명지대학교 미래정치연구소 2019 미래정치연구 Vol.9 No.2

선거경쟁도는 선거품질인식에 부정적 영향을 주는가? 미국선거에 관한 기존의 경험연구들은 경쟁도가 높은 선거일수록 선거와 정부에 대한 부정적 인식이 커진다는 점을 발견해 왔고, 이는 민주주의 이론의 기대와 반대되는 경험적 발견이다. 본 연구는 선행연구들의 일반적 발견들을 부정하지 않으면서도, 선거경쟁도가 유권자들의 선거품질 인식에 미치는 간접적 효과를 간과했다고 주장한다. 이론적으로 선거구 수준에서 선거경쟁도는 투표참여율을 견인하고, 이와 같이 상승된 선거분위기는 유권자들의 선거품질인식에 긍정적 영향을 미칠 수 있다. 2016년 한국 총선 유권자 설문자료와 다층모델을 활용하여 분석한 결과, 선거구 선거경쟁도는 유권자들의 선거품질에 긍정적 및 부정적 효과를 동시에 가지는데, 긍정적 효과가 부정적 효과에 비해 큰 것으로 나타났다. 분석 결과는 기존의 경험연구들을 부정하지 않으면서도 선거경쟁도의 민주적 효과를 보여주었다는 의의를 가진다. Does electoral competitiveness lead to a negative evaluation of election quality among voters? Prior studies on US legislative elections have consistently found that highly contested elections breed public negativity about elections and the government, which contradicts democratic theories. While we agree with these studies, we argue that they neglect the indirect effects of electoral competitiveness on perceived election quality. We contend that electoral competitiveness increases turnout at the district level and that the increased turnout, in turn, promotes perceived election quality at the individual level. Using multilevel mediation modeling and responses from survey data from the 2016 Korean legislative election, we found empirical evidence that electoral competitiveness has both positive and negative effects on perceived election quality. However, the positive effect is greater than the negative one, thereby supporting democratic theories while not rejecting altogether the prior studies against competitive elections.

LoRa Network based Parking Dispatching System

Youngho Cho(조영호),Yeong Geon Seo(서영건),Dae-Yul Jeong(정대율) 한국디지털콘텐츠학회 2017 한국디지털콘텐츠학회논문지 Vol.18 No.7

The purpose of this study is to develop an intelligent parking dispatching system based on LoRa network technology. During the local festival, many tourists come into the festival site simultaneously after sunset. To handle the traffic jam and parking dispatching, many traffic management staffs are engaged in the main road to guide the cars to available parking lots. Nevertheless, the traffic problems are more serious at the peak time of festival. Such parking dispatching problems are complex and real-time traffic information dependent. We used Queuing theory to predict inbound traffics and to measure parking service performance. Q-learning algorithm is used to find fastest routes and dispatch the vehicles efficiently to the available parking lots.