Highly Conductive Paper/Textile Electrodes Using Ligand Exchange Reaction-Induced in Situ Metallic Fusion

Kang, Sungkun,Nam, Donghyeon,Choi, Jimin,Ko, Jongkuk,Kim, Donghee,Kwon, Cheong Hoon,Huh, June,Cho, Jinhan American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.12

<P>Here, we report that metal nanoparticle (NP)-based paper/textile electrodes with bulk metallic conductivity can be prepared via organic linker-modulated ligand exchange reaction and in situ room-temperature metallic fusion without additional chemical or thermal treatments. For this study, amine-functionalized molecule linkers instead of bulky polymer linkers were layer-by-layer (LbL)-assembled with tetraoctylammonium bromide (TOABr)-stabilized Au NPs to form Au NP multilayered films. By conversion of the amine groups of the organic molecule linkers from −NH<SUB>3</SUB><SUP>+</SUP> to the −NH<SUB>2</SUB> groups, as well as by a decrease in the size of the organic linkers, the LbL-assembled Au NPs became highly interconnected and fused during LbL deposition, resulting in Au NP multilayers with adjustable conductivity and transport behavior. These phenomena were also predicted by a density functional theory investigation for the model system. Particularly, LbL-assembled films composed of TOABr-Au NPs and diethylenetriamine (<I>M</I><SUB>w</SUB>: ∼104) exhibited a remarkable electrical conductivity of 2.2 × 10<SUP>5</SUP> S·cm<SUP>-1</SUP>, which was higher than the electrical conductivity of the metal NP-based electrodes as well as the carbon material-based electrodes reported to date. Furthermore, based on our approach, a variety of insulating flexible papers and textiles were successfully converted into real metal-like paper and textile electrodes with high flexibility preserving their highly porous structure. This approach can provide a basis for further improving and controlling the electrical properties of flexible electrodes through the control of organic linkers.</P> [FIG OMISSION]</BR>

The effect of virtual body swapping with mental rehearsal on pain intensity and body perception disturbance in complex regional pain syndrome

Hwang, Haesol,Cho, Sungkun,Lee, Jang-Han Wolters Kluwer Health | Lippincott Williams Wilkin 2014 International journal of rehabilitation research Vol.37 No.2

The present study investigated the effects of virtual body swapping with mental rehearsal on pain intensity and body perception disturbance (BPD) in patients with complex regional pain syndrome. Patients with complex regional pain syndrome were assigned randomly to three experimental groups: the ‘virtual body swapping with mental rehearsal’ (VBS) group (n=13), the ‘watching movement only’ group (n=13), and the ‘mental rehearsal only’ (n=13) group. Then, pretreatment pain intensity and BPD were compared with post-treatment perceptions. The results showed that pain intensity did not decrease significantly after treatment in all of the groups. However, BPD improved significantly after treatment in the VBS group, but not in the other groups. Therefore, this study is the first to show the effects of a single session of VBS on BPD. Further studies should apply an elevated degree of immersion and create a more realistic virtual body.

통증경험에 대한 해석편향 수정 프로그램의 효과성 검증

박혜진(Hyejin Park),조성근(Sungkun Cho) 대한스트레스학회 2020 스트레스硏究 Vol.28 No.2

두려움-회피 모형에서는 통증의 발달 및 유지에 있어 해석편향이 중요한 역할을 한다고 강조한다. 이 연구에서는 통증에 대한 해석편향을 수정하는 것이 통증경험에 어떠한 영향을 미치는지 알아보기 위해 남녀대학생 53명을 대상으로 통증경험(강도, 역치, 인내)에 대한 해석편향 수정 프로그램(interpretation bias modification for pain: IBM-P)의 효과를 검증했다. 연구결과, 훈련집단은 통제집단에 비해 IBM-P 이후 해석편향 및 부정정서가 유의하게 감소했고, 통증역치는 증가했다. 또한 통증역치에 대한 IBM-P의 효과는 수정된 해석편향이 매개하는 것으로 나타났다. 이는 IBM-P가 통증경험의 완화를 위한 치료 프로그램으로 활용될 수 있음을 시사한다. Background: Fear-avoidance model for pain suggests interpretation bias affects subsequent pain experience. However, limited research has been conducted on the role of interpretation bias in a subjective pain experience. The purpose of this study was to investigate the efficacy of interpretation bias modification for pain outcomes (i.e., pain intensity, threshold, and tolerance). Methods: 53 healthy university students were randomly assigned to either the training (n=28) or the control group (n=25). Interpretation bias and negative emotion were assessed before and after conducting the interpretation bias modification for pain (IBM-P). During a cold pressor task, pain outcomes were measured. Results: Results indicated that the training group showed significantly decreased interpretation bias and negative emotion than the control group after the IBM-P. Also, participants in the training group was found to have a greater pain threshold during the cold pressor task than those in the control group. Furthermore, the IBM-P effect on increased pain threshold was mediated by post-interpretational bias. Other pain outcomes and mediating effect of post-interpretational bias on the negative emotion were not significant. Conclusions: Results highlight that interpretation bias is modifiable and plays an important role in pain outcomes. Thus, using IBM-P for pain patients can be a useful application to alleviate their pain outcomes. Future research should consider the precise role of interpretation bias that affects patient’s pain outcomes.

통증 위협이 회피행동에 미치는 영향

이유빈(Ubin Yi),조성근(Sungkun Cho) 대한스트레스학회 2019 스트레스硏究 Vol.27 No.1

통증 두려움과 회피행동은 통증의 만성화를 초래한다. 통증이 발생하면 인간은 본능적으로 회피행동전략을 사용하게 된다. 그러나 사회적 지지가 부여될 경우 동일하게 통증 관련 위협을 경험함에도 회피행동 억제효과를 나타낼 가능성이 있다. 이 연구에서는 대학생 연인 80쌍을 대상으로 통증 관련 위협과 연인관계인 이성의 사회적 지지가 회피행동에 미치는 영향을 실험적으로 확인하고자 했다. 실험결과 고통증 위협 조건에서 사회적 지지를 받은 경우 사회적 지지를 받지 않은 집단에 비해 과제수행 지연시간이 유의하게 짧았으나 저 통증 위협 조건에서는 사회적 지지 조건에 따른 유의한 차이가 없었다. 더욱이 사회적 지지는 두려움 감소에 영향을 미치지 않았다. 끝으로 본 연구의 의의와 한계점을 살피고, 추후 연구에 대해 제안했다. Background: According to the fear-avoidance model, pain becomes chronic when it is related to fear and avoidance behavior. When a pain-related threat occurs, humans instinctively use avoidance behavior strategies. However, the support of significant others is likely to inhibit avoidance behavior even with the same pain-related threat stimulus. Thus, in this study, we examined the effects of pain-related threats and social support of romantic partner on avoidance behavior inhibition. Methods: Participants consisted of 80 pairs of healthy undergraduate couples, and were randomly assigned to one of four group conditions in a 2×2 factorial design, with threat level (high/low) and social support (presence/absence) as factors. Results: The results of the experiment indicated a significant interaction between threat level and social support. Specifically, in the high-threat condition, when social support was provided, task delay time was significantly shorter than when no social support was provided. On the other hand, in the low-threat condition, the time delay difference between high- and low- social support group was not significant. Moreover, social support did not affect fear reduction. Conclusions: These results indicate that avoidance behaviors, which are instinctive responses to pain, can be inhibited by social support. This result would enhance understanding of the factors that have not been described in the fear-avoidance model in the pain-chronicization process, and will help expand and improve the model. We also discuss possible limitations of the study and scope for further studies.

Role of affective instability on suicidal risk in complex regional pain syndrome: a diary approach (preliminary report)

( Saetbyeol Jeong ),( Jeongwi An ),( Sungkun Cho ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.1

Background: Many patients with complex regional pain syndrome (CRPS) have been known to be at risk of suicide, due to severe pain and its comorbid conditions. The risk of suicide may be associated with affective instability, which is an indicator of emotional dysregulation. Particularly, unstable shifts in negative emotions are difficult to cope with, which may result in individuals feeling uncontrollable, hopeless, and entrapped. This study aimed to examine the role of affective instability in the relationship between pain intensity and suicide risk (suicidal ideation and impulsivity) in patients with CRPS, by employing a daily diary. Methods: Twenty-three patients registered at the CRPS Association in Korea were asked to complete a day-to-day routine for 15 days, followed by a diary composed of pain intensity, suicidal ideation, impulsivity, and positive and negative affects. Results: Results showed that the interactions between negative affective instability and daily pain intensity were statistically significant on daily suicidal ideation (coefficient = 0.41, t (21) = 2.56, P < 0.050) and daily impulsiveness (coefficient = 1.20, t (19) = 3.35, P < 0.010). However, those between positive affective instability and daily pain intensity were not. Conclusions: This study is the first attempt to investigate the role of affective instability on the relationship between daily pain intensity and daily suicide risk in patients with CRPS. Our findings suggest that health professionals pay considerable attention to the instability of negative affects when assessing and managing patients with CRPS at risk of suicide.

중요한 타인의 정서적 지지 편차 변동성이 복합부위통증증후군환자의 일상생활기능에 미치는 영향: 일지연구

유현경(Hyunkyung Yoo),정태진(Taejin Jeong),조성근(Sungkun Cho) 대한스트레스학회 2020 스트레스硏究 Vol.28 No.4

이 연구에서는 복합부위통증증후군(CRPS) 환자를 대상으로 지각한 정서적 지지와 선호하는 정서적 지지 간의 편차의 변동성이 환자의 통증강도와 일상생활 기능의 관계에 미치는 영향을 확인하고자 했다. 21명의 CRPS 환자를 대상으로 15일 간의 일지연구를 실시한 결과 정서적 지지 편차 변동성의 조절효과가 유의하게 나타났다. 정서적 지지 편차의 변동성이 작을 때는 통증강도가 증가할 때 일상생활 기능에 미치는 영향에 차이가 없으나, 클 때는 통증강도가 증가할수록 일상생활 기능에 미치는 부정적 영향이 증가했다. 이러한 결과는 사회적 지지의 완충효과 모델을 지지하는 결과로, 환자가 요구하는 정도의 정서적 지지를 일관적으로 제공하는 것이 CRPS 환자의 일상생활 기능 유지에 기여할 수 있음을 시사한다. Background: Daily functioning is an important aspect of chronic pain management, particularly for individuals living with complex regional pain syndrome (CRPS). Previous studies have established that emotional support from significant others is beneficial for chronic pain patients. However, emotional support can be discrepant from one’s preference and can also fluctuate. Thus, the present study investigates the role of instability in emotional support discrepancy on the daily functioning of patients with CRPS. Methods: Participants consisted of 21 CRPS patients. Google Forms was used to obtain daily diary ratings over 15 days. The mean square of successive differences was calculated as an indicator of instability of emotional support discrepancy. Statistical analysis was conducted using hierarchical linear modeling. Results: Hierarchical linear modeling reveals that the moderating effect of instability in emotional support discrepancy on the relationship between daily pain severity daily activity avoidance (coefficient=0.01, t (292)=5.57, p<.001), activity interference (coefficient=0.01, t (292)=5.98, p<.001), distraction (coefficient=0.01, t (292)=5.10, p= .007) was statistically significant. Conclusions: The results of this study suggest that instability in emotional support discrepancy reduces the buffering effect of emotional support.

전기자동차용 지로터 오일 펌프의 치형 간극에 따른 성능 특성 해석

정윤상(Yunsang Jeong),조준영(Junyoung Cho),김성근(Sungkun Kim) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

Assessment of factors affecting the difficulty of caudal epidural injections in adults using ultrasound

Kim, Young Hoon,Park, Hue Jung,Cho, Sungkun,Moon, Dong Eon Pulsus Group Inc 2014 Pain research & management : the journal of the Ca Vol.19 No.5

<▼1><P>Caudal epidural block is used to treat pain in the lower back and lower extremities. The procedure can be difficult to perform, particularly when a blind technique is being used. The authors of this study aimed to identify variables affecting the difficulty of caudal epidural blocks performed using a blind technique by measuring relevant anatomical variables using ultrasonography.</P></▼1><▼2><P><B>BACKGROUND:</B></P><P>In unaided caudal epidural block (CEB), incorrect needle insertion has been reported to occur in 15% to 38% of attempts.</P><P><B>OBJECTIVE:</B></P><P>To statistically analyze the anatomical variables affecting difficult CEB using ultrasonographic measurement.</P><P><B>METHODS:</B></P><P>Preprocedural ultrasonography was performed and the following measurements were obtained in 146 patients: the distance from the skin to the apex of the sacral hiatus; the depth of the sacral canal at the apex of the sacral hiatus; the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base; the distance from the skin to the apex of the sacral cornu; and the distance between the apexes of bilateral cornua. One clinician, unaware of the ultrasonographic findings, performed the injections using the landmark technique. The procedures were videotaped and were subsequently reviewed by an independent investigator.</P><P><B>RESULTS:</B></P><P>The means (± SDs) of the abovementioned measurements were 12.1±3.7 mm, 6.1±2.1 mm, 25.9±7.4 mm, 10.0±4.0 mm and 16.4±3.2 mm, respectively. Injections failed in 16 (11%) patients and were defined as difficult in 21 (14.4%) patients. The depth of the sacral canal at the apex of sacral hiatus (P<0.001) and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base (P=0.001) were significant predictors of difficult CEB. Of all patients, 85.7% and 75.2% were correctly classified as difficult or not difficult, respectively. The cutoff values of the depth of the sacral canal at the apex of the sacral hiatus and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and the sacral base to predict a difficult CEB were 3.7 mm and 17.6 mm, respectively.</P><P><B>CONCLUSIONS:</B></P><P>Both the depth of the sacral canal at the apex of the sacral hiatus and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base are significant variables affecting the difficulty of the CEB.</P></▼2>

Characteristics of Diverse Verbal Pain Descriptors in South Korean Patients With Peripheral Neuropathic Pain: ‘Jeorim’ (Tingling) and ‘Sirim’ (Cold) as Key Neuropathic Pain Descriptors

Kyomin Choi,Ohyun Kwon,Bum Chun Suh,Jeeyoung Oh,Sungkun Cho,Eunhee Sohn,In Soo Joo 대한신경과학회 2023 Journal of Clinical Neurology Vol.19 No.3

Background and Purpose The description of pain is the most-important indicator leading to the adequate treatment of patients with neuropathic pain (NeP). The purpose of this study was to identify and characterize the unique features of Korean verbal descriptions in patients with peripheral NeP. Methods This study included 400 patients (167 males and 233 females) and their 1,387 paindescription responses. Patients with peripheral NeP freely described their symptoms in Korean. Collected verbal descriptions were grouped according to terminologies with similar meanings. Participants completed validated patient-reported outcome scales including the neuropathic pain symptom inventory (NPSI) and painDETECT questionnaire (PD-Q). The frequencies of each verbal pain descriptor were compared between the NPSI and PD-Q scores. Results ‘Jeorim’ (tingling) was the most common among 17 types of organized verbal pain descriptors, and the ‘Sirim’ (cold) symptom had a significantly higher rate of use in the 2 highseverity groups when participants were classified by their total scores on the NPSI and PD-Q. Conclusions Korean verbal NeP descriptors were significantly diverse. The Jeorim (tingling) and Sirim (cold) descriptors can be utilized in evaluations of Korean patients with NeP.

통증 두려움과 회피행동의 관계에 금전동기가 미치는 영향

김분옥(Bun-Ok Kim),김기성(Kiseong Kim),신대용(Daeyong Shin),조성근(Sungkun Cho) 대한스트레스학회 2019 스트레스硏究 Vol.27 No.1

본 연구 목적은 통증 두려움이 금전동기에 따라 회피행동에 미치는 영향을 살펴보는 것이다. 건강한 남녀 80명을 대상으로 통증 두려움과 금전동기 조건에 따라 4집단 중 1개 집단에 무선 할당했다. 실험결과, 고-통증 두려움 집단이 저-통증 두려움 집단에 비해 영상 시청과 과제 수행 동안 자율신경계가 더욱 활성화되었다. 또한 통증 두려움과 금전동기 조건에 따라 회피행동에 미치는 상호작용 효과가 유의했다. 저-통증 두려움 집단에서는 금전동기 조건에 상관없이 과제 수행 지연시간에 유의한 차이가 없었던 반면, 고-통증 두려움 집단에서는 금전동기가 높을수록 과제 수행 지연시간이 유의하게 더 짧았다. 본 연구는 수정된 두려움-회피 모형을 지지하는 경험적 증거를 제공하며 경쟁목표 차단 기제의 발현을 실험적으로 증명한다. Background: The purpose of this study was to examine the effects of monetary motivation on the relationship between pain-related fear and avoidance behavior. Methods: Eighty healthy volunteers were randomly assigned to one of four groups in accordance with task conditions of pain-related fear (high or low) and monetary motivation (high or low). Results: The autonomic nervous system was more active in the high pain-related fear group than in the low pain-related fear group as the participants watched a video and performed a task. Also, pain-related fear and monetary motivation had a significant interaction effect on avoidance behavior. High monetary motivation was associated with a shorter delay time during task performance in the high pain-related fear group. No significant difference was observed in the delay time in the low pain-related fear group. Conclusions: This study provides empirical evidence supporting the modified fear-avoidance model and experimentally proves the activation of the goal shielding mechanism.