Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells

Min-Seung Choi,Young-Ju Lee,Jung-Dae Kwon,Yongsoo Jeong,Ju-Yun Park,강용철,Pung Keun Song,Dong-Ho Kim 한국물리학회 2013 Current Applied Physics Vol.13 No.8

We investigated the effects of hydrogen plasma treatment on the physical and electrical properties of fluorine-doped tin oxide (FTO) films used for amorphous silicon (a-Si) thin film solar cells. A slight increase in carrier concentration by the hydrogen doping effect was observed for the FTO film exposed to the hydrogen plasma for 5 min. For further exposure to the plasma, the chemical reduction became prominent and resulted in deterioration of the electrical and optical properties of the film. XPS analysis revealed that the chemical reduction of SnO2 to Sn metallic state occurs on the surface region. It was found that the defects formed by hydrogen plasma act as recombination centers at the interface between FTO electrode and p-layer of a-Si solar cells. This phenomenon resulted in the deterioration of the cell performance. The averaged conversion efficiency (6.82%) of the cells on pristine FTO hydrogen substrate was decreased to 5.81% for the cells on FTO treated for 5 min, which is mainly attributed to the decrease in short-circuit current density.

안와골절의 외과적 접근에 대한 증례보고

민승기,이은택,오승환,이동근,고세욱,송종민,최성림 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.3

The Orbital fracture which is often combined with midface fracture can cause decreased visual acuity, limitation of eyeball movement, diplopia, enophthalmos, etc. Traumatic orbital fracture causes change of orbital volume, results in diplopia and enophthalmos thus, accurate repositioning of displaced bone and reconstruction of orbital defect with autogenous materials(cranial, rib, iliac bone, cartilage and fascia lata) or alloplastic materials(gelatin film, polyglactin mesh, methylmethacrylate, Teflon, silicone, Supermid, hydroxyapatite and metal). The key point of reconstruction of orbit is accurate repositioning of displaced orbital floor, lateral, medial orbital wall and sufficient bonegraft in anatomical defect. As this cases, we obtained good results through transconjunctival and coronal approach who were required orbital reconstruction. Also, we accurately diagnosed orbital fracture with C.T., 3D model and good result for orbital reconstruction with sufficient parietal block bone graft during average 16.8 months follow-up.

Differential Effects of Pioglitazone in the Hippocampal CA1 Region Following Transient Forebrain Ischemia in Low- and High-Fat Diet-Fed Gerbils.

Moon, Seung Myung,Choi, Goang-Min,Yoo, Dae Young,Jung, Hyo Young,Yim, Hee Sun,Kim, Dae Won,Hwang, In Koo,Cho, Byung Moon,Chang, In Bok,Cho, Sung-Min,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2015 Neurochem Res Vol.40 No.5

<P>In the present study, we investigated the effects of pioglitazone (PGZ) in the hippocampal CA1 region of low- or high-fat diet (LFD or HFD) fed gerbils after transient forebrain ischemia. After 8 weeks of LFD or HFD feeding, PGZ (30 mg/kg) was intraperitoneally administered to the gerbils, following which ischemia was induced by occlusion of the bilateral common carotid arteries for 5 min. Administration of PGZ significantly reduced the ischemia-induced hyperactivity 1 day after ischemia/reperfusion in both LFD- and HFD-fed gerbils. At 4 days after ischemia/reperfusion, the neurons were significantly reduced and microglial activation was observed in the hippocampal CA1 region in LFD- and HFD-fed gerbils. The microglial activation was more prominent in the HFD-fed gerbils compared to the LFD-fed gerbils. Administration of PGZ ameliorated ischemia-induced neuronal death and microglial activation in the hippocampal CA1 region 4 days after ischemia/reperfusion in the LFD-fed gerbils, but not in the HFD-gerbils. At 6 h after ischemia/reperfusion, tumor necrosis factor-α (TNF-α) and interlukin-1β (IL-1β) levels were significantly increased in the hippocampal homogenates of LFD-fed group compared to control group, and HFD feeding further increased TNF-α and IL-1β levels. PGZ treatment significantly ameliorated the increase of TNF-α and IL-1β levels in LFD-fed gerbils, not in the HFD-fed gerbils. At 12 h after ischemia/reperfusion, superoxide dismutase (SOD) and malondialdehyde (MDA) levels in hippocampal homogenates were significantly increased in the LFD-fed group compared to the control group, and HFD feeding significantly showed relatively reduction in SOD activity and increase in MDA level. PGZ administration significantly reduced the increase in MDA levels 12 h after ischemia/reperfusion in the LFD-fed gerbils, but not in the HFD-fed gerbils. These results suggest that PGZ ameliorates the neuronal damage induced by ischemia by maintaining the TNF-α, IL-1β, SOD and MDA levels in LFD-fed gerbils. In addition, HFD feeding affects the modulation of these parameters in the hippocampus after transient forebrain ischemia.</P>

The effects of secondary task on the control of vehicle under driving simulator: a study among 50s taxi drivers

Han Soo Kim,Jin Seung Choi,Dong Won Kang,Hong Won Yeon,Mi Hyun Choi,Doo Hwan Ji,Byung Chan Min,Soon Cheol Chung,Gye Rae Tack 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

Objective: The aim of this study is to quantitatively evaluate the effects of the secondary task during simulated driving using the variable indicating control of vehicle. Background: There are so many researches for simulated driving and performance. For instance, some researches show that the effects of cell phone conversations on simulated driving. Cell phone conversations impaired explicit recognition memory. Method: Participants included 50s taxi drivers; 15 males and 15 females. All subjects were instructed to keep a distance (30m) from the car ahead and a constant speed (80km/hr or 100km/hr). Sending text message (STM) and Searching navigation (SN) were selected as the secondary task. Experiment consisted of rest for 3min., driving alone for 1min. and driving with secondary task for 1 min.. We were analyzed anterior-posterior coefficient of variation (APCV) and medial-lateral coefficient of variation (MLCV). Results: APCV was increased by 175.4% in STM and 223.8% in SN at 80km/hr. MLCV was increased by 242.3% in STM and 323.4% in SN at 100km/hr. There was no significant difference between genders. Conclusion: Consequently, performing secondary task during driving impaired the control of vehicle.

Controlled post-sulfurization process for higher efficiency nontoxic solution-deposited CuIn_0.7Ga_0.3Se₂ absorber thin films with graded bandgaps

Jang, Jin Woo,Lee, Seung Min,Choi, Ik Jin,Cho, Yong Soo ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.710 No.-

<P><B>Abstract</B></P> <P>A practical way of adjusting post-sulfurization process with variable durations is proposed to improve the cell-conversion efficiency of non-toxic solution driven CuIn<SUB>0.7</SUB>Ga<SUB>0.3</SUB>Se<SUB>2</SUB> absorber thin films. The degree of bandgap grading was controllable by changing the sulfurization time from 2 min to 30 min due to the dissimilar distribution of sulfur across the absorber layer. Deeper intensified distributions of Ga and S were responsible for enhancements in the open-circuit voltage and cell-conversion efficiency. A competitive efficiency of ∼8.81% for the 10 min-sulfurized CIGSSe cell was achieved with other promising parameters, i.e., short-circuit current density of 33.17 mA/cm<SUP>2</SUP>, open-circuit voltage of 0.496 V, and fill factor of 53.5%, resulting from the improved carrier collection and reduced recombination by the bandgap grading. This improved efficiency corresponds to a ∼15.6% enhancement compared to the unsulfurized sample.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Controlled post-sulfurization process enhances cell efficiency of CuIn<SUB>0.7</SUB>Ga<SUB>0.3</SUB>Se<SUB>2</SUB>. </LI> <LI> Sulfur penetrates easily toward the back contact with concentration gradient. </LI> <LI> A graded bandgap structure is responsible for the improved charge collection. </LI> <LI> The achieved cell efficiency of ∼8.81% corresponds to the ∼15.6% enhancement. </LI> <LI> Actual bandgap variations are projected on the basis of elemental distributions. </LI> </UL> </P>

Purification and Characterization of Helicobacter pylori ${\gamma}$-Glutamyltranspeptidase

Song, Jae-Young,Choi, Yeo-Jeong,Kim, Jeong-Min,Kim, Yoo-Ree,Jo, Jin-Seong,Park, Jin-Sik,Park, Hee-Jin,Song, Yun-Gyu,Lee, Kon-Ho,Kang, Hyung-Lyun,Baik, Seung-Chul,Youn, Hee-Shang,Cho, Myung-Je,Rhee, Kw The Korean Society for Microbiology 2011 Journal of Bacteriology and Virology Vol.41 No.4

Gamma-glutamyltranspeptidase (GGT) was purified to electrophoretic homogeneity from the cell extract of H. pylori. The purified enzyme consisted of heavy and light subunits with molecular weights of 38 kDa and 21 kDa, respectively. N-terminal amino acid sequence of heavy and light subunits revealed that H. pylori GGT was processed into 3 parts for a signal peptide of 27 amino acid residues, a heavy subunit of 352 residues, and a light subunit of 188 residues during translation. The reaction rate for hydrolysis of ${\gamma}$-GpNA was 84.4 ${\mu}mol/min$ per milligram of protein, and that for the ${\gamma}$-glutamyl transfer from ${\gamma}$-GpNA to gly-gly was 23.8 ${\mu}mol/min$ per milligram of protein. The apparent Km values of H. pylori GGT for ${\gamma}$-glutamyl compounds were on the order of $10^{-3}$ to $10^{-4}$ M and those for acceptor peptides and amino acids were on the order of $10^{-1}$ to $10^{-2}$ M. The GGT protein kept approximately 80% of the initial enzymatic activity on incubation at $60^{\circ}C$ for 15 min. The optimum temperature and pH for reactions of both hydrolysis and transpeptidation were $40^{\circ}C$ and 9.0, respectively. The transpeptidation and hydrolysis reactions catalyzed by H. pylori GGT were strongly inhibited by L-Gln and moderately inhibited by L-Ala, L-Ser, ${\beta}$-chloro-L-Ala, and L-Glu. These results demonstrated that the biochemical properties of H. pylori GGT are different from those of other bacterial GGTs. Further, H. pylori GGT might degrade glutathione in the gastric mucous layer of humans if the enzyme could be secreted in the bacterial niches.

Flavobacterium meningosepticum에 의한 균혈증 1예

장성원,유진홍,진승원,김선우,김연식,박순민,이대훈,최민호,최주연,신완식,강문원,강지민 대한화학요법학회 1997 대한화학요법학회지 Vol.15 No.1

1996년 6월 카톨릭대학교 부천성가병원에 뇌경색으로 입원했던 61세 남자 환자의 혈액에서 Flavobacterium meningosepticum을 분리하였다. 환자는 폐렴을 동반한 패혈증의 예로 ceftriaxone과 metronidazole을 투여하였으나 입원 48시간만에 사망하였다. Flabovacterium meningosepticum is a rae cause of nosocomial infection which shows multi-drug resistance. It mainly invades patients with impaired immunity. Recently, we experienced a case of F. meningosepticum bacteremia in a patient with chronic debilitated state owing to stroke. The clinical progress was so rapid that he died within 48 hours. Blood culture revealed F. meningosepticum which showed characteristic yellow colony in blood agar plate.

백서의 심실세동성 심정지 모델에서 해마신경세포 손상에 대한 단백질 합성저해제의 효과

오동렬,채장성,박승현,김세경,최세민,박제영 대한응급의학회 2000 대한응급의학회지 Vol.11 No.4

Background: The goal of successful resuscitation is not only to stop the process of ischemia as soon as possible but also to overcome the secondary injury process after resuscitation, which involves a complex interplay of mechanisms. Brain damage accompanying cardiac arrest and resuscitation is frequent and devastating. Cells die by one of two mechanisms: necrosis or delayed neuronal death. Delayed neuronal death may require protein synthesis. Neurons in the CA1 subfield of the hippocampus are selectively vulnerable to death after injury by ischemia and reperfusion. Death of these neurons occurs after an interval of 1 or 2 days. We assessed the effects of a protein synthesis inhibitor, cycloheximide(CHX), on hippocampal neuronal death of rats by using the ventricular fibrillation cardiac arrest(VFCA) model. Methods: The effect of CHX(3 mg/kg, s.c.) on hippocampal neuronal death was studied in two groups of 18 rats each, one group being subjected to a 2-min VFCA and the other to a 3-min VFCA. Each group was divided into three subgroups: control(groupⅠ,Ⅱ) without subcutaneous injection of CHX, "esp-12" of group Ⅰ/Ⅱ treated with CHX 12 hours after return of spontaneous circulation (ROSC), and "exe-24" of group Ⅰ/Ⅱ treated with CHX 24 hours after ROSC. The coronal sections of the hippocampus levels were stained with hematoxylin-eosin after 72 hours of survival. The histologic damage score(HDS) was used to assign a score to the total number of damaged neurons counted in each of the hippocampal CA1 subfields. Results: 1. There were not significant differences in heart rates, blood pressures, blood sugar, and blood gas in group I & Ⅱ during the pre-arrest steady state or at 5 min and 30 min after ROSC. 2. In group I & Ⅱ, the HDS, were significantly reduced in rats(I exp-12, 1.1 ±0.6;Ⅰexp-24, 1.3 ±0.5;Ⅱ exp-12, 1.4±0.7; and Ⅱ exp-24, 1.8±0.8) treated with CHX 12 hours or 24 hours after ROSC than control rats(1,2.5 ±0.9;Ⅱ,2.9±0.8)(p<0.05). Conclusion: These results suggest that delayed hippocampal neuronal death from ischemic insult after ventricular fibrillation cardiac arrest followed by resuscitation can be prevented by a protein synthesis inhibitor, CHX. Further experimental studies of the action mechanism of protein synthesis inhibitors to delayed neuronal death and clinical applications are required.

Sustained-release praziquantel tablet : pharmacokinetics and the treatment of clonorchiasis in beagle dogs

Hong, Sung-Tae,Lee, Sang Hyup,Lee, Seung-Jin,Kho, Weon-Gyu,Lee, Mejeong,Li, Shunyu,Chung, Byung-Suk,Seo, Min,Choi, Min-Ho 梨花女子大學校 藥學硏究所 2003 藥學硏究論文集 Vol.- No.12

Praziquantel is rapidly absorbed and secreted; and thus fractional doses are recommended for the treatment of cestode and trematode infections. In the present study, we developed a new praziquantel tablet formula allowing sustained-release (SRP). In vitro dissolution of SRP tablets showed that praziquantel at 300 ㎎/tablet combined with hydroxypropyl methylcellulose dissolved completely at a constant rate over 10 h, whereas the conventional praziquantel tablet (PZQ) was only 40% dissolved. Pharmacokinetic studies in dogs confirmed that SRP was absorbed more slowly than PZQ. The mean value of the area under the concentration/time curve from 0 h to the final observation time, the maximum concentration in serum, and the time of maximum concentration in serum for SRP were 3.471.500 ng/min for 0.25 ㎖, 10,300 ng for 0.25 ㎖, and 192 min. while the values for PZQ were 688,600 ng/min for 0.25㎖, 2,500 ng for 0.25㎖, and 135 min. The cure rate in dogs with a heavy infection (500 metacercariae) treated with a single dose of SRP (150 ㎎/tablet) at 50 ㎎/㎏ was 80%, while in dogs treated with a single dose of SRP (300 ㎎/tablet) at 30 mg/kg it was 60%, and the cure rate with PZQ was 20%. In each case. the egg reduction rate was similar (over 90%). No abnormal liver functions or hepatic or renal pathologies were observed in dogs administered with SRP at 30 ㎎/㎏. The SRP tablet showed sustained release and slow absorption; and it had an improved anthelmintic efficacy against Clonorchis sinensis in experimental dogs. compared with conventional praziquantel.

고등어(Scomber japonicus ) 치어의 마취제로서 Clove oil, MS-222 및 2-Phenoxyethanol의 평가

한석중 ( Seock Jung Han ),김경민 ( Kyong Min Kim ),최낙중 ( Nack Jung Choi ),구준호 ( Jun Ho Koo ),박충국 ( Chung Kug Park ),이원교 ( Won Gyo Lee ),지승철 ( Seung Chul Ji ) 한국수산과학회(구 한국수산학회) 2011 한국수산과학회지 Vol.44 No.6

The efficiency of clove oil, MS-222, and 2-phenoxyethanol was evaluated as anesthetics in juvenile Scomber japonicus . Stage A5 of anesthesia was assumed to be sufficient for conducting routine aquaculture procedures in less than 3 min, with recovery (stage R5) in less than 5 min. The lowest effective doses of the three anesthetics were 50 mg L-1 clove oil (anesthetic time of 71.3 s and recovery time of 167.0 s), 100 mg L-1 MS-222 (anesthetic time of 70.7 s and recovery time of 115.7 s), and 400 mg L-1 2-phenoxyethanol (anesthetic time of 86.7 s and recovery time of 95.0 s). Anesthetic times decreased with increasing doses for all three anesthetic agents, and fish anesthetized with clove oil exhibited the longest recovery times. After 30 min, the highest plasma cortisol and lactate levels were detected with the use of clove oil, whereas the lowest values were observed with 2-phenoxyethanol. In addition, high glucose levels were maintained during recovery with clove oil, but the treatments did not significantly differ. The most effective of the three anesthetic agents was 2-phenoxyethanol, although all were considered acceptable for use in cultures of juvenile Scomber japonicus