Selective electrochemical reduction of carbon dioxide to formic acid using indium-zinc bimetallic nanocrystals

Kwon, Ik Seon,Debela, Tekalign Terfa,Kwak, In Hye,Seo, Hee Won,Park, Kidong,Kim, Doyeon,Yoo, Seung Jo,Kim, Jin-Gyu,Park, Jeunghee,Kang, Hong Seok The Royal Society of Chemistry 2019 Journal of Materials Chemistry A Vol.7 No.40

<P>For the electrochemical reduction of CO2 (CRR) with high selectivity for HCOOH, In-Zn bimetallic nanocrystals (NCs) were synthesized as catalysts by <I>in situ</I> reduction of In2O3-ZnO NCs with various compositions. All In-containing bimetallic catalysts exhibited excellent selectivity to produce HCOOH, while Zn NCs favor CO production. A composition with In : Zn = 0.05 has higher catalytic activity than In NCs, with a faradaic efficiency of 95% and a HCOOH production rate of 0.40 mmol h<SUP>−1</SUP> cm<SUP>−2</SUP> at −1.2 V <I>vs.</I> RHE. The enhanced catalytic performance is in part ascribed to the fewer surface oxide layers, which increase the conductivity and facilitate the charge transfer. Density functional theory calculations revealed that the In-Zn interfacial sites make the HCOOH pathway significantly energy-favorable, which supports the higher production rate of Zn0.95In0.05 than that of In.</P>

Comparison of clinical characteristics and prognosis of pneumocystis jirovecii pneumonia in patients with immunocompromised and non-immunocompromised conditions

( Hong-joon Shin ),( Min-seok Kim ),( Bo Gun Kho ),( Ha Young Park ),( Tae-ok Kim ),( Cheol-kyu Park ),( Yong-soo Kwon ),( In-jae Oh ),( Yu-il Kim ),( Sung-chul Lim ),( Young- Chul Kim ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Background: Pneumocystis jirovecii pneumonia (PCP) is a fatal respiratory infection frequently associated with immunocompromised (IC) conditions. Although PCP has been reported in non-immunocompromised (non-IC) patients, however, few studies have been conducted. This study was aimed to compare the clinical characteristics and prognosis of PCP in IC and non-IC patients. Methods: We retrospectively analyzed patients who were suspected of having PCP with polymerase chain reaction (PCR) test positive for Pneumocystis jirovecii from January 2013 to May 2019. IC group was classified into human immunodeficiency virus (HIV), hematologic, solid organ tumor, rheumatologic and immunosuppressive agent group. Results: A total 192 PCP cases including 176 IC cases and 16 non-IC cases were analyzed. Patients were older in the non-IC group compared with the IC group (72.5 vs. 62.0, P=0.002). Hematologic malignancy was the most common (47.2%), followed by HIV (14.8%) in the IC group. The interval between test for PCP-PCR and PCP treatment was shorter in the IC group compared with non-IC group (0 [0-3] vs. 4.0 [2.2-7.7] days, P=0.001). In-hospital mortality was not significantly different between IC and non-IC groups (43.2% vs. 62.5%, P=0.189). Age (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.02-1.09; P=0.002) and PaO₂/FiO₂ (OR 0.99; 95% CI 0.98-1.00; P=0.039) were the prognostic factors for in-hospital mortality in the multivariate logistic regression analysis. There was no significant difference between IC and non-IC group in 6-month survival. However, HIV group had better 6-month survival compared with non- IC group in the subgroup analysis (Hazard ratio 0.16; 95% CI 0.05-0.53; P=0.003]. Conclusion: Patients with PCP in non-IC group were older than IC group, and had similar prognosis as other IC group except HIV group.

中學校 科學科의 實驗實習敎材의 開發硏究Ⅱ

朴泳喆,韓麟傳,李春雨,權寧駿,朴弘緖 공주대학교 사범대학 과학교육연구소 1982 과학교육연구 Vol.14 No.1

In this study a few laboratory teaching materials have been developed to be available for the effective performance of experiments and practices- a heart of inquiry learning-as a continuance of 'A study on the Development of Laboratory Teaching Materials for Middle School Science Course I' The present condition of science education has been investigated by means of questionaires, interviews and literature, the results of the present condition and problems in junior high schools are as follows: 1. The hours for science classes are considerably little for the teaching contents of science textbooks. 2. The level of teaching is beyond the student's capability in terms of their experience and intellectual development. 3. Science teachers are overburdened with much tasks, and laboratories and laboratory facilities are too insufficient and furthermore teaching is mainly conducted on the lecture method as a preperation for various entrance exams. 4. Teachers' eagerness and desirable attitude for teaching are required. In this study, materials for every branch of science have been developed to be available for the effective performance of experiments and practices through inquiries. The materials developed in this study are as follows: 1. In physics, measure apparatus of extremely small masses, length, and very little time intervals are developed. 2. In chemistry, new methods for gas generating apparatus and materials. are developed. 3. In biology, the size of quadrate and the method to decide the time in facilitating for the purpose of survey of botany community are introduced. The results of the investigation of natural enemy on Hyphantria cunea, and the study on collecting, breeding of Planaria are also shown. 4. In earth science, the laboratory teaching materials are developed for observing continuous spectrum and line spectrum. Putting the above results of study together, the suggestions are made to the effect as follows: 1. The quantity of learning should be reduced and the levels lowered in the new textbooks. 2. The development and distribution of various teaching materials(film, T,P., cassettes film, supplementary, textbook, program teaching material, individual learning material) is required. 3. The experimental instruments should be timely manufactured and distributed on the basis of effective administrative support to ensure their solidity and accuracy. 4. The concrete design to eliminate the teacher's burden should be contrived and the system for senion teachers in charge of science teaching in secondary schools, should be improved. 5. Teacher's research activities should be encouraged through various research institutes(Institute of science education , graduate school of education and the other research institutes.) 6. The disposition of laboratory assistant should be considered. 7. More positive supports from other societies relevant with education are much expected to be made.

In-vitro and In-vivo Anti-hyperglycemic Effects of Nipa palm (Nypa fruticans Wurmb) Extract

Kyung-Tae Kwon,Gi Jung Kim,Tae Yang Kim,Jin-A Yu,Su-Young Lee,Ji-Yoon Hong,Ye Lim Jang,Tessema Haimanot Miticu,Young-In Kwon 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

In this study, Nipa palm extract by solvent were investigated for their anti-hyperglycemic and using in-vitro, in-vivo animal models. In-vitro study, we investigated the inhibitory activities of Nipa palm stems and flower extracts by solvent against various digestive enzymes such as α-glucosidase, sucrase, maltase, and glucoamylase. In addition, α-amylase inhibitory activity, oxygen radical absorbance capacity, total phenolic and flavonoid content were measured. Among solvent extract, stem water extract (SWE) had the highest α-glucosidase inhibitory activity (3.6 mg/ml of IC50) and high sucrase inhibitory activity (0.28 mg/ml IC50). Furthermore, the extracts were investigated for in-vivo post-prandial blood anti-hyperglycemic effect using Sprague-Dawley(SD) rat model. The maximum blood glucose concentration(Cmax) in SWE-treated SD-rat (0.5 g-ΚBE/kg-bw) was significantly lower than in untreated SD-rats (199.9±10.4 vs. 222.0±15.4 hr·mg/dL, p<0.05). These results indicate that SWE may improve exaggerated post-prandial spikes in blood glucose via inhibition of intestinal α-glucosidase and thus delays carbohydrate absorption in colon.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

Transfer of ultrathin molybdenum disulfide and transparent nanomesh electrode onto silicon for efficient heterojunction solar cells

Kang, Sung Bun,Kwon, Ki Chang,Choi, Kyoung Soon,Lee, Rochelle,Hong, Kootak,Suh, Jun Min,Im, Min Ji,Sanger, Amit,Choi, In Young,Kim, Soo Young,Shin, Jae Cheol,Jang, Ho Won,Choi, Kyoung Jin Elsevier 2018 Nano energy Vol.50 No.-

<P><B>Abstract</B></P> <P>Two-dimensional transition-metal dichalcogenides (TMDCs) are very promising for photovoltaic (PV) applications due to their excellent light absorption properties and appropriate bandgap energy, Although multifunctional applications of TMDCs in photovoltaic devices have been achieved, the photovoltaic conversion efficiency under 1 sun is still very low with small active area because of their inexpedient high sheet resistance and limitation of synthesis techniques. In this study, we demonstrate uniform synthesis of 4-in. wafer-scale MoS<SUB>2</SUB> thin films by thermal decomposition of solution precursors. The solar cells are fabricated by transferring n-MoS<SUB>2</SUB> thin films on p-Si substrates to form p-n heterojunctions and then transferring Au nanomeshes prepared in a novel surface treatment as transparent top electrodes onto MoS<SUB>2</SUB>. The circular n-MoS<SUB>2</SUB>/p-Si heterojunction solar cell exhibited a power conversion efficiency of 5.96% at a diameter of 0.3 in. and proved to be easily scalable to 1-in. diameter with 5.18% efficiency. To the best of our knowledge, the solar cells of this study are the most efficient and the largest in all types of solar cells based on TMDC reported so far. Finally, based on finite difference time-domain simulation, we proposed a strategy for implementing n-MoS<SUB>2</SUB>/p-Si heterojunction solar cell with efficiency higher than 15% by introducing optimal doping control of n-MoS<SUB>2</SUB> and efficient anti-reflection layers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The large scale, uniform (4-in.) MoS<SUB>2</SUB> thin films are synthesized. </LI> <LI> High transparent, low sheet resistances electrodes are fabricated in a novel way. </LI> <LI> The efficient MoS<SUB>2</SUB> based solar cells are developed by all transfer process including top electrodes. </LI> <LI> The highest, largest MoS<SUB>2</SUB> p-Si/ heterojunction solar cells are demonstrated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P> <B>The highest performance (5.96%), largest area (1 in.) n-MoS2/p-Si solar cells with transparent electrodes fabricated by a novel way.</B> The transparent electrodes lowers the series resistance of the fabricated solar cells, facilitating the collection of photo-generated carriers from the junction. In our knowledge, we have achieved the highest photovoltaic performance at largest active area by using transparent nanomesh electrode among TMDC based solar cells.</P> <P>[DISPLAY OMISSION]</P>

大邱市民의 牛乳消費實態와 仁識度

朴恒均,張仁浩,權海秉,金永洪 경북대학교 교육대학원 1977 논문집 Vol.9 No.-

This survey is for getting references to establish a plan for increasing milk demands and the improvement of dairy hygiene by studing the amount of milk consumption, tendency of milk consumers and the recognition of milk in Daegu City. One hundred eighteen thousand and three hundred seventy four homes of pupils who are attending the elementary school in Daegu-City were surveyed for milk consumed or not and 1,280 homes consumed milk and 1,561 homes, non-drinking milk were studied from September 28, 1977 to October 10, 1977 as follows: 1) The annual consumption of milk is 11,497M/T, 4.65% of 247,000M/T national milk production. And dairy cattles fed in Daegu area are 4,752, 4.13% of 115,000 heads fed in Korea. 2) Daily consumption milk is 31,000㎏ and a shortage of 5,000㎏ arose in the summer while there was a 8,000-9,000㎏ over abundance in the winter. 3) Home delivered milk for 118,374 homes that have pupils was 10,560, 8.92%. 4) According to monthly income, 29.7% of 1,280 homes delivered milk was less than 100,000 Won for monthly earnings, and 43.7% for 1,561 homes not delivered milk was less than 1000,000Won for monthly earnings. The number of homes that were not delivered milk was two times as much as home consumed milk. 5) Depending on housewife's school career, middle school graduates were 33.0%, high school 66.9% while among homes that had not consumed milk, 46.37% housewife attended middle school and 49.6% high school. 6) If the price is lower than now, homes requiring more milk was 84.6% but childrens high school year. And if it was low price, 88.4% homes wanted to begin drinking milk, 35.43% by their children's high school year. This indicates that an increasing number of homes required milk. 7) The consumption of 2 bottles (360㎖) or more per homes is 79.69% and one bottle (180㎖) per home is 20.31%. 8) Homs delivered for one year more were 75.7% and less than one year 34.6%. 9) Delivered milk placed in refrigerators was 69% and others 31.4%. People who drank cold milk was 81.56% and hot milk were 18.44% 10) Milk price delivered was: A high of 45.94% and a low of 2.97% and a reasonable 51.09%. 11) The reasons for drinking milk were: Weakened body 49.6%, taste 18.04%, and instead of a rice meal 31.02%. 12) The physical effects after drinking were: Good 65.47%, bad 0.5%. 13) Homes which liked to have delivered milk in the morning were 85.31% and daily 97.19%. 14) Milk quality was: Good 27.89% and normal or of poor grade 72.8%. 15) Milk delivery systems were: Good 65.31% and not good 29.65%. 16) The mainreason for not drinking milk taste 20.88%, Yogurt used instead 20.50%, and powdered milk used instead 22.74%, and unwholesome milk 16.02%.

외과계 감염증에 대한 Sulperazon(Sulbactam/cefoperazone) 및 Cefoperazone의 임상효과 비교연구

박규주,노동영,김상준,권오중,정중기,홍인규 대한화학요법학회 1990 대한화학요법학회지 Vol.8 No.2

Despite recent advances in development of antibiotics and antiseptic techniques, infection still remains to be one of the major problems in the surgical field. Due to development of bacterial resistance to commonly used antibiotics, there is always a need to develop a new antimicrobial agent which would overcome such resistance. Sulperazon (Sulbactam/Cefoperazone) is a combination drug of potent β-lactamase inhigitor, sulbactam, and cefoperazone which has broad antibacterial spectrum, which was developed to combat against β-lactamase producing microorganisms. In an effort to evaluate the efficacy and safety of sulperazone, we have randomly divided 40 patients (12 with perforated appendicitis, 10 with peritionitis, 6 with GB empyema, 6 with periproctal abscess, 3 with wound infection, 1 liver abscess, 1 pancreatic abscess, and 1 acute cholangitis) into 2 groups (20 patients in each group). One group received daily dose of 2 to 3 grams of sulperazon and the other group received daily dose of 2 to 3 grams of cefoperazone. Following results were obtained : 1. Clinical effect of sulperazon was cure in 16 patients (80%), improvement in 3 patients (15%), compaired to cure in 14 patients (70%), improvement in 4 patients (20%) for the cefoperazone group. 2. Using disc diffusion method, sulperazon was sensitive to all of the isolated microorganisms except β-hemolytic streptococci, which was moderately sensitive. Cefoperazone was sensitive to only E. coli, Pseudomonas aeruginosa and Serratia. 3. Microbiological effect of sulperazon was eradication of offending microorganisms in 16 patients (80%), compared to 14 patients (70%) in Cefoperazone group. 4. Overall clinical efficacy of sulperazon was 95%, compared to 80% for cefoperazone. 5. Adverse effects due to sulperazon was nausea and diarrhea which occurred in 1 patient respectively. 2 patients receiving cefoperazone experienced diarrhea. It can be concluded that sulperazon is a safe and effective antibiotic agent which can be used in surgical infection patients.

Compression injury of the circular stapler for gastrointestinal end-to-end anastomosis: preliminary in-vitro study

손경모,Myeong Sook Kwon,Hong-min Ahn,In Young Lee,김건호,남경원,JoonWon Lee,Chang-Suk Kong 대한외과학회 2020 Annals of Surgical Treatment and Research(ASRT) Vol.99 No.2

Purpose: This preliminary in-vitro study was designed to evaluate the risk factors of compression injury from use of a circular stapler for end-to-end anastomosis. Methods: Transparent collagen plates were prepared in dry and wet conditions. Physical properties of collagen plates and porcine colon tissue were examined using a rheometer. Adjustable and fixed-type circular staplers were applied on the collagen plates and the gap distance and compressive pressure were measured during anvil approximation. Tissue injury was evaluated using a compression injury scale. Compression properties were accessed to optimal or overcompression based on gap distance. Results: Unacceptable injuries were rarely observed on the dry collagens, regardless of compression device. In the adjustable compression, the compressibility ratio was similar between dry and wet collagen. Overcompression and unacceptable injury increased on the wet collagens. In the fixed compression, the compressibility ratio increased significantly and unacceptable injuries were observed in more than 50% of wet collagens. Peak pressure was significantly higher in the fixed-compression types than those of adjustable type. On bivariate correlation analysis, fixed-compression type and wet collagens were respectively associated with overcompression. On multivariate analysis, edematous collagen condition was the most important risk factor and proximal anvil side, fixed compression type, and overcompression were also independent risk factors for unacceptable compression injury. Conclusion: In the edematous tissue condition, unintentional overcompression could be increased and result in tissue injury on the compression line of the circular stapler.

담도결석환자의 총수담관내 담즙에서 세균성장과 β-glucuronidase 활성도

이동기,홍사준,배선우,권상옥,장인호,김미라,강명서,이경원 연세대학교 원주의과대학 1992 원주의대논문집 Vol.5 No.1