Redox-Dependent Spatially Resolved Electrochemistry at Graphene and Graphite Step Edges

Gü,ell, Aleix G.,Cuharuc, Anatolii S.,Kim, Yang-Rae,Zhang, Guohui,Tan, Sze-yin,Ebejer, Neil,Unwin, Patrick R. American Chemical Society 2015 ACS NANO Vol.9 No.4

<P>The electrochemical (EC) behavior of mechanically exfoliated graphene and highly oriented pyrolytic graphite (HOPG) is studied at high spatial resolution in aqueous solutions using Ru(NH<SUB>3</SUB>)<SUB>6</SUB><SUP>3+/2+</SUP> as a redox probe whose standard potential sits close to the intrinsic Fermi level of graphene and graphite. When scanning electrochemical cell microscopy (SECCM) data are coupled with that from complementary techniques (AFM, micro-Raman) applied to the same sample area, different time-dependent EC activity between the basal planes and step edges is revealed. In contrast, other redox couples (ferrocene derivatives) whose potential is further removed from the intrinsic Fermi level of graphene and graphite show uniform and high activity (close to diffusion-control). Macroscopic voltammetric measurements in different environments reveal that the time-dependent behavior after HOPG cleavage, peculiar to Ru(NH<SUB>3</SUB>)<SUB>6</SUB><SUP>3+/2+</SUP>, is not associated particularly with any surface contaminants but is reasonably attributed to the spontaneous delamination of the HOPG with time to create partially coupled graphene layers, further supported by conductive AFM measurements. This process has a major impact on the density of states of graphene and graphite edges, particularly at the intrinsic Fermi level to which Ru(NH<SUB>3</SUB>)<SUB>6</SUB><SUP>3+/2+</SUP> is most sensitive. Through the use of an improved voltammetric mode of SECCM, we produce movies of potential-resolved and spatially resolved HOPG activity, revealing how enhanced activity at step edges is a subtle effect for Ru(NH<SUB>3</SUB>)<SUB>6</SUB><SUP>3+/2+</SUP>. These latter studies allow us to propose a microscopic model to interpret the EC response of graphene (basal plane and edges) and aged HOPG considering the nontrivial electronic band structure.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-4/acsnano.5b00550/production/images/medium/nn-2015-00550c_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b00550'>ACS Electronic Supporting Info</A></P>

扶正益氣方의 抗癌活性과 免疫調節作用에 관한 硏究

具滋權,宋昊哲,金東熙,徐榮培,朴陽春,金聖勳 대한본초학회 2000 大韓本草學會誌 Vol.15 No.1

To evaluate the antitum or activity and immune response Bujungikgibang(BJ1GB) studies were done experimentally. The results were obtained as follows: 1. BJIGB extracts exhibited a weak cytotoxicity against SK-OV-3, and SK-MEL-2 cell lines. While it showed cytotoxicity against B16-Fl0 cell line up to 30% of control at concentration of 0.5 mg/ml. 2. BJIGB extracts significantly showed inhibitoty effect on DNA topoisomerase 1 from calf thymus in a dose-dependant manner. 3. BJIGB extracts showed antiadhesive rates against A549, at 30% at 0.5 mg/ml, 60% at 1 mg/ml 4. BJIGB extracts inhibited CAM angiogenesis up to 60%. 5. BJIGB extracts prolonged life span of ICR mice bearing S-180 sarcoma cells up to 130.5%. 6. In FACS analysis, the population of helper T cell was increased weakly, while cytotoxity T cell was decreased insignificantly. 7. The production of nitric oxide in RAW cell stimulated by LPS was incresed at 0.5mg/ml or more in dose dependant fashion as compared with control. 8. Proliferation rate of splenocyte was increased at 0.5mg/ml or more a dose dependant fashion as compared with control. These results suggested that BJIGB extracts might be usefully applied for treatement of cancer and also it was nesessary to do more studies about its mechnisms.

암 생쥐에서 Testosterone으로 인한 유해감각예민도 둔화와 이에 대한 Naloxone의 차단효과

양구범,박제민,김명정,전명호,이국희 대한생물치료정신의학회 2000 생물치료정신의학 Vol.6 No.1

In order to examine the effect of testosterone on antinociception and the role of opioid system as an underlying mechanism, thirty-seven adult female mice(Institute of Cancer Research) were randomized to Naloxone(n=18) and Control group(n=19). Testosterone propionate(1mg/kg, ip) with naloxone HCL(2mg/kg, ip) or with normal saline(5ml/kg, ip) was administered on the first and the third experimental days. Nociceptive sensitivity was measured by Tail flick test(TFL, sec) before and after injection on the first and the third experimental days. The same dose of testosterone was injected on the second experimental day. The results were as follows; 1.TFL of control group was significantly increased by testosterone. TFL of control group measured on the first experimental day before and after injection were 5.5±1.1 sec(mean±sd) and 6.3±1.2 sec, respectively, and the change was significant(t=4.06, p=0.001). That measured on the third experimental day before injection was 5.9±1.0, showing a significant increase compared to that of the first experimental day(t=2.37, p=0.029). 2.Testosterone-induced antinociception was blocked by naloxone. In naloxone group, change in TFLs measured before(5.6±0.8) and after(5.3±0.9) injection was not significant on the first experimental day. On the third day, TFL measured before injection(6.6±1.2) was increased significantly than that of the first experimental day(t=2.87, p=0.011), but it decreased to baseline level after injection of naloxone(5.3±1.3; t=4.73, p=0.000). From these results, it is suggested that testosterone has antinociceptive effect, which is mediated by endogenous opioid system.

정신과 외래에서 향정신성약물을 복용 중인 환자에서의 하지불편증후군

지구덕,한승희,양명성,양창국 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.4

Objectives : The purpose ofthis study was to investigate the clinical characteristics and incidence of restless legs syndrome (RLS) in outpatients with psychiatric iltness. Methods : 146 adult patients (male 52, female 94) wcre selected from those who visited a psychiatric outpatient clinic. RLS was evaluated through an interview method using diagnostic criteria and a severity rating scale for RLS developed by the Intemational RLS Study Group (IRLSSG). The authors also applied Beck's Depression Inventory (BDI), Beck's Anxiety Inventory (BAI), the Pittsburgh SleeP Quality Index, Bames Akathisia Rating Scale and neurological examination. Rcsults : Thirty-four (23.3%) among 146 subjects were diagnosed as having RLS. Fifteen (44.1%) among those 34 RLS patients reported to have developed their RLS after starting their psychotropic agents and only 4 patients (11.7%) had Cu-rrently been receiving treatment for their RLS. The RLS group showed higher BDI and BAI scores (p<0.01) and lower sleep quality (p<0.01) compared to those of non-RLS. The RLS group also showed a significantly higher co-morbidity of Pa-rasomnias (χ²=8.5, P<0.01) and peripheral neuropathy (χ²=5.2, P<0.05). Conclusion : The results from this study suggest that a substantial proportion of outpatients with psychiatric illness are suffering RLS. Our data suggest that clinicians should pay attention to the possible presence of RLS among their patients who are taking psychotropic agents.

간질환자들의 자기공명영상소견

주양구,손철호 啓明大學校 醫科大學 1995 계명의대학술지 Vol.14 No.4

To evaluate the causes of the epileptic seizure and the usefulness of the MR imagings for detection, localization, and differentiation of structural epileptogenic abnormalities. We retrospectively reviewed 101 patients who had seizure episodes and had undergone brain MRI for recent 1 years. The causes of the seizure were classified into brain atrophy, traumatic or post-operative lesions, congenital or developmental anomaly, tumor, vascular malformation, white matter disease, infectious disease and others. The location of the lesions were classified onto diffuse, frontal, parietal, temporal, occipital and others. Fourty-two of the 101 patients had brain atrophy, 23 patients had lesions secondary to trauma or surgery, 12 had congenital or developmental anomaly, seven had tumor, six had vascular malfomation, four had white matter disease, two had infectious disease, and five others had two arachnoid cysts, one hydrocephalus, one eclampsia, and one tuberous sclerosis. The lesions were located at the parietal lobe in 17 patients, frontal lobe in 15, temporal lobe in 21, and occipital lobe in four. MR imaging is the technique of choice when examining a patient who is having seizures. Detection, localization, and differentiation of structural epileptogenic abnormalities are much better with MR imaging than other diagnostic method.

초·중학교 육상선수의 참여형태에 따른 참여동기와 만족도

강양구,오수일 江原大學校附設體育科學硏究所 2004 江原大學校附設體育科學硏究所論文集 Vol.- No.27

The purpose of this study was to provide hilpful basic data for P.E. teachers making efforts to find and cultivate players and personnel concerned contributing to operating a track&field contest and developing programs by examining. Participation motive and satisfaction by track players' Participation type in elementary and middel school. A questionnaire survey was conducted with subjects of 444 persons in total 17 groups. 5 point Likert scale was used for the survey. Collected materials was calculated with standard deviation and average by sex, school grade and Participation type. Also t-test was applied to analyse the result. The results of the study are as follow: First of all, women were higer than men in Participation motive by whole sex based on questions related to health and sociality. Second, respondents of middle school showed higher Participation motive than those of elementary school by school grade based on questions related to relationships and performance ability. Third, long-term continuous Participants were higher than short-term Participants in Participation motive by Participation type based on questions related to health, achievement feelings and positive consideration, but that was contrary in questions related to performance ability. Fourth, men were higher than women in the degree of satisfaction based on questions concerned with interest, pride, health, professional intellect, facilities and place and teaching skill by whole sex. Fifth, middle school was higher than elementary school in the degree of satisfaction by school grade based on questions concerned with health, facilities and place. Lastly, long-term continuous Participants were higher than short-term Participants in the degree of satisfaction by Participation type based on questions concerned with health, interest, pride and specialized knowledge.

Slim Patch Type을 이용한 카페인의 경피흡수에 관한 연구

김정수,권동환,임도형,김구서,강진양 한국약제학회 2006 Journal of Pharmaceutical Investigation Vol.36 No.2

遠心펌프回轉車內의 壓力特性에 關한 實驗的 硏究

朴伊東,金東燮,權養球 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.2

The distribution of pressure in an impeller of a centrifugal pump was investigated to operate under the optimum, conditions according to the variation of dynamic factors such as rotational speed and flowrate in an impeller. The interchange of energy actually are as follows. 1) The variations of pressure in the radial direction had almost the same patterns as the flowrate was changed and the outlet pressure decreased with the increase of the flowrate. 2) It showed that the pressure increased in the radial direction of impeller as the rotational speed increased, and the same phenomenon took place with the variation of flowrate. Otherwise there was little recovery of pressure in the region of low rotational speed and high flowrates(5.0, 5.5 lps) . 3) The head-flowrate of the characteristic curves increased simultaneously according to the increase of rotational speed, and the power gradient of the power-flowrate curve increased as the rotational speed increased and the efficiency-flowrate curve showed that the efficiency was the same in a low flowrate and higher in a high flowrate according to the increase of rotational speed.

찬물 강제수영이 남성화된 암컷 생쥐의 통각예민도에 미치는 영향

이국희,박제민,김명정,양구범,전명호 대한생물치료정신의학회 2001 생물치료정신의학 Vol.7 No.1

The aim of the study was to test the hypothesis that the mice androgenized in their perinatal period show in their later life heightened basal pain sensitivity and lowered analgesic effect induced by cold water swim. Entered into the experiment were 29 female mice androgenized by intraperitoneal injection of 100㎍ testoste-rone propionate within 24 hours after birth and 30 female mice given with intraperitoneal injection of the same amount of normal saline as the control group. On 160th day after birth, the pain sensitivity was measured in terms of the tail flick latency using 52±1℃ water before and after forced swim in cold water(15±1℃) for six minutes to see the change of the pain sensitivity. The results were as follows 1) The androgenized mice revealed significantly heightened basal pain sensitivity as compared to the control mice. 2) The lowering effect of the pain sensitivity by cold water forced swim was significant in both the androgenized and the control groups, but the effect was significantly less in the androgenized mice than in the control group. From these results, the author suggests that the androgenized female mice exposed to the testosterone in the neonatal period have heightened basal pain sensitivity and lowered cold water swim-induced analgesia than the normal female mice in their later lives.

Flutamide가 수컷 생쥐의 유해감각예민도에 미치는 영향

장세헌,김명정,박제민,양구범,한병득 대한생물치료정신의학회 2000 생물치료정신의학 Vol.6 No.1

Objectives : Previous findings on nociception modulatory effect of testosterone were controversial. In this study, androgen receptor antagonist flutamide was used to reveal testosterone effect on baseline nociceptive sensitivity and stress-induced antinociception in male mice. Methods : Experiments consist 3 Parts: 1) tail flick latency(TFL, sec, 52±1℃) was measured before and 30 minutes after intraperitoneal injection of flutamide 150, 100, 50mg/kg or vehicle(N=15 for each group); 2) TFL was measured before and after serial injection of LHRH antagonist antide(1mg/kg, ip), and 30 minutes after flutamide(100mg/kg, ip) or vehicle; 3) With pretreatment of flutamide(100mg/kg, ip) or vehicle(N=15 for each group), TFL was measured before and after 5 minutes of forced-swim in cold water(15±1℃). Results : 1.TFL was significantly elongated(hypoalgesic) in the flutamide 100 and 150mg/kg groups. TFL of flutamide 150mg/kg group was significantly longer than 50mg/kg group. 2.Though pretreatment with antide itself did not make any change in TFL, it blocked antinociceptive effect of flutamide. TFL was elongated by serial injections in both flutamide and control group. 3.TFL was elongated by FS in both flutamide and control group. FS-induced elongation of TFL was significantly more prominent in flutamide group. Conclusions : From these results, it is suggested flutamide has antinociceptive effect on baseline TFL and potentiates FS- induced antinociception.