• Title/Summary/Keyword: K-40

Search Result 43,032, Processing Time 0.068 seconds

Heterogeneous Electron Transfer at Polyoxometalate-modified Electrode Surfaces

  • Choi, Su-Hee;Seo, Bo-Ra;Kim, Jong-Won
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.1
    • /
    • pp.104-111
    • /
    • 2010
  • The heterogeneous electron transfer at $SiMo_{12}O_{40}^{4-}$ monolayers on GC, HOPG, and Au electrode surfaces are investigated using cyclic voltammetric and electrochemical impedance spectroscopic (EIS) methods. The electron transfer of negatively charged $Fe(CN)_6^{3-}$ species is retarded at $SiMo_{12}O_{40}^{4-}$-modified electrode surfaces, while that of positively charged $Ru(NH_3)_6^{3+}$species is accelerated at the modified surfaces. This is due to the electrostatic interactions between $SiMo_{12}O_{40}^{4-}$ layers on surfaces and charged redox species. The electron transfer kinetics of a neutral redox species, 1,1‘-ferrocenedimethanol (FDM), is not affected by the modification of electrode surfaces with $SiMo_{12}O_{40}^{4-}$, indicating the $SiMo_{12}O_{40}^{4-}$ monolayers do not impart barriers to electron transfer of neutral redox species. This is different from the case of thiolate SAMs which always add barriers to electron transfer. The effect of $SiMo_{12}O_{40}^{4-}$ layers on the electron transfer of charged redox species is dependent on the kind of electrodes, where HOPG surfaces exhibit marked effects. Possible mechanisms responsible for different electron transfer behaviors at $SiMo_{12}O_{40}^{4-}$ layers are proposed.

A Study on Kazakh Women's Consumer Behavior

  • Potluri, Rajasekhara Mouly;Abikayeva, Marina;Usmanova, Nelya;Challagundla, Srilakshmi
    • The Journal of Industrial Distribution & Business
    • /
    • v.5 no.4
    • /
    • pp.5-11
    • /
    • 2014
  • Purpose - This paper examines Kazakh women's spending patterns and buying behavior. Research design, data, and methodology - After thoroughly reviewing the related literature on consumer behavior in general, and female consumer behavior in particular, both questionnaires and in-depth personal interviews were used to collect data from 400 Kazakh women consumers equally chosen from the age groups 20-30, 30-40, 40-50, and above 50. Results - A stratified and convenient sample was employed, and the selected five hypotheses were proved using the Karl Pearson Coefficient of Correlation. Related to spending patterns, 40 and 35 percent of the 20-30 and 30-40 age groups, respectively, of Kazakh women spend their incomes on personal items, as against 30 percent from both the 40-50 and 50 and above age groups. Twenty-five and 35 percent of the 40-50 and 50 and above age group, respectively, take decisions based on product quality, whereas this percentage is at its mite in the below 40 age group. Conclusions - The buying behavior of Kazakh women consumers is revealed; the results proffer useful background information to formulate marketing strategies.

Trends in Incidence of Breast Cancer among Women under 40 in Asia

  • Keramatinia, Aliasghar;Mousavi-Jarrahi, Seyed-Houssein;Hiteh, Mohsen;Mosavi-Jarrahi, Alireza
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.3
    • /
    • pp.1387-1390
    • /
    • 2014
  • Background: The aim of this study was to evaluate trends in incidence of breast cancer in women less than 40 years in Asia. Materials and Methods: Registered cases of female breast cancer age less than 40 years and corresponding person years were ascertained from the CI5plus for 10 registries in Asia for the duration of 1970- 2002. Cases were categorized into three age groups: 16-40, 16-29, and 30-40. The 16-40 age group was adjusted to world age population structure. Joinpoint regression analysis was conducted to determine the annual percent of change (APC) and the average annual percent of change (AAPC) for each age group. Results: A total of 23,661 cases of breast cancer occurred in the 10 registries during the 32 years (1970-2002) of follow-up. The overall age adjusted (16-40 group) breast cancer incidence rate increased from 2.28-4.26 cases per 100,000 population corresponding to an AAPC of 2.6% (95%CI 2.1, 3.0). The trend in incidence for the age group 16-29 increased from 0.45-1.07 corresponding to an AAPC of 2.8% (95%CI 1.9, 3.7). In age group 30 to 40, the incidence ranged from 13.3 in year 1970 to 24.8 in year 2002 corresponding to an AAPC of 2.7% (95% CI 2.3, 3.1). There were two statistically significant changing points in the regression line for the age groups 30-40 and 16-40: one point in the year 1975 with an APC of 6.1 (5.1, 7.1), and the other in 1985 with an APC of 0.4% (0.01, 0.8). Conclusions: Our study proved that: 1) the incidence of breast cancer in young women has increased in Asian population during the study period; 2) the rate of increase was very high during the period of 1980-1990.

Control of Catalytic Properties of Heteropoly Acid by Blending it with a Polymer (고분자와의 블랜딩에 의한 헤테로폴리산의 촉매 특성 제어)

  • Song, In Kyu;Lee, Jong Koog;Lee, Wha Young
    • Applied Chemistry for Engineering
    • /
    • v.5 no.5
    • /
    • pp.819-824
    • /
    • 1994
  • A membrane-like $H_3PMo_{12}O_{40}$-polysulfone film was prepared by blending $H_3PMo_{12}O_{40}$ with polysulfone using dimethylformamide as a common solvent. SEM and EDX analysis showed that $H_3PMo_{12}O_{40}$ was uniformly and finely distributed in the film catalyst. The ESCA measurement also revealed that the oxidation state of Mo was not changed. The $H_3PMo_{12}O_{40}$-polysulfone catalyst showed lower activity for acid-catalyzed reaction and higher activity for oxidation reaction than $H_3PMo_{12}O_{40}$ in ethanol conversion reaction. The oxidation activity of the film catalyst was about 10 times higher than $H_3PMo_{12}O_{40}$. The decrease of acidic activity was due to DMF strongly adsorbed in acid sites of $H_3PMo_{12}O_{40}$, whereas the increase of oxidation activity was mainly due to uniform distribution of $H_3PMo_{12}O_{40}$. Adsorption results showed that the surface character of $H_3PMo_{12}O_{40}$ was drastically increased, while the bulk property of that was almost same after blending. It is suggested that the control of surface/bulk property as well as acid/redox property of heteropoly acid would be possible by blending it with a polymer.

  • PDF

Fly Ash Application for Reduction of Acid Mine Drainage (AMD) as Runoff and Leachate Released from Mine Waste Disposal Sites

  • Oh, Se Jin;Moon, Sung Woo;Oh, Seung Min;Kim, Sung Chul;Ok, Yong Sik;Lee, Bup Yeol;Lee, Sang Hwan;Yang, Jae E.
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.47 no.6
    • /
    • pp.533-539
    • /
    • 2014
  • Mine wastes such as acid mine drainage (AMD) can cause the detrimental effects on surrounding environment, thereby eventually threatening human health. Main objective of this study was to evaluate the neutralizing effect of fly ash (FA) as a stabilizing material AMD. Field plot was constructed in a coal waste depot which has caused aluminium-whitening adjacent to the stream. Different mixing ratios of FA were applied on a top of the soil, and then the physicochemical properties of runoff and soil were monitored. Constructed plots were as following: control (mine waste only (W)), mine waste + 20% ($w\;w^{-1}$)of FA (WC20M), mine waste + 40% ($w\;w^{-1}$)of FA (WC40M), and WC40M dressed with a fresh soil at the top (WC40MD). Result showed that initial pH of runoff in control was 5.09 while that in WC40M (7.81) was significantly increased. For a plot treated with WC40M, the concentration of Al in runoff was decreased to $0.22mg\;L^{-1}$ compared to the W as the control ($4.85mg\;L^{-1}$). Moreover, the concentration of Fe was also decreased to less than half at the WC40M compared to the control. Application of FA can be useful for neutralizing AMD and possibly minimizing adverse effect of AMD in mining area.

Development of the 40m SANS Instrument at HANARO for Nanostructure Characterization (나노구조 분석을 위한 하나로 40m 소각중성자산란장치 개발)

  • Choi Sung-Min;Kim Tae-Hwan;Lee Ji-Hwan;Han Young-Soo;Lee Chang-Hee
    • Journal of the Korean Vacuum Society
    • /
    • v.14 no.3
    • /
    • pp.126-131
    • /
    • 2005
  • Small-angle neutron scattering (SANS) is a very powerful techniques for nanostructure characterization. In this paper, we report the conceptual design and technical description of the 40 in small angle neutron scattering (SANS) insoument which is being developed by KAIST and KAERI for installation at 30 MW HANARO research reactor. For the optimal design of 40 m SANS, a series of computer simulation were pe.to.mod. The Q-.ange of the 40m SANS inst.ument is $0.0005\;\AA^{-1}-1.0\AA^{-1}$ which is a world top-class SANS Q-range. When the cold neutron spectrum used in the simulation is realized, the neutron flux at sample position is expected to be comparable to the current state-of-art SANS instrument in the world.

CD40 Co-stimulation Inhibits Sustained BCR-induced $Ca^{2+}$ Signaling in Response to Long-term Antigenic Stimulation of Immature B Cells

  • Nguyen, Yen Hoang;Lee, Ki-Young;Kim, Tae-Jin;Kim, Sung-Joon;Kang, Tong-Mook
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.15 no.3
    • /
    • pp.179-187
    • /
    • 2011
  • Regulation of B cell receptor (BCR)-induced $Ca^{2+}$ signaling by CD40 co-stimulation was compared in long-term BCR-stimulated immature (WEHI-231) and mature (Bal-17) B cells. In response to long-term pre-stimulation of immature WEHI-231 cells to ${\alpha}$-IgM antibody (0.5~48 hr), the initial transient decrease in BCR-induced $[Ca^{2+}]_i$ was followed by spontaneous recovery to control level within 24 hr. The recovery of $Ca^{2+}$ signaling in WEHI-231 cells was not due to restoration of internalized receptor but instead to an increase in the levels of $PLC{\gamma}2$ and $IP_3R-3$. CD40 co-stimulation of WEHI-231 cells prevented BCR-induced cell cycle arrest and apoptosis, and it strongly inhibited the recovery of BCR-induced $Ca^{2+}$ signaling. CD40 co-stimulation also enhanced BCR internalization and reduced expression of $PLC{\gamma}2$ and $IP_3R-3$. Pre-treatment of WEHI-231 cells with the antioxidant N-acetyl-L-cysteine (NAC) strongly inhibited CD40-mediated prevention of the recovery of $Ca^{2+}$ signaling. In contrast to immature WEHI-231 cells, identical long-term ${\alpha}$-IgM pre-stimulation of mature Bal-17 cells abolished the increase in BCR-induced $[Ca^{2+}]_i$, regardless of CD40 co-stimulation. These results suggest that CD40-mediated signaling prevents antigen-induced cell cycle arrest and apoptosis of immature B cells through inhibition of sustained BCR-induced $Ca^{2+}$ signaling.

Effects of Deletion of P, Ca, Zn, Mg, Fe, K, Mn, or Se from Mineral Premix in the Diets Containing $40\%$ Fish Meal on Growth Performance of Juvenile Korean Rockfish (Sebastes schlegeli) (어분이 $40\%$ 함유된 배합사료에 P, Ca, Zn, Mg, Fe, K, Mn과 Se 무 첨가가 조피볼락의 성장에 미치는 효과)

  • LEE Sang-Min;PARK Sung-Real;KIM Tae Jin;MEONG Jeong-In;CHANG YoungJin
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.31 no.2
    • /
    • pp.252-258
    • /
    • 1998
  • A feeding experiment was conducted to investigate the effects of deletion of P, Ca, Zn, Mg, Fe, K, Mn, or Se from mineral premix in the diets containing $40\%$ fish meal on growth performance of juvenile Korean rockfish. Three replicate groups of the fish initially averaging 5.4 g were fed the experimental diets deleted one ot each mineral (P, Ca, Zn, Mg, Fe, K, Mn, Se or all) in the mineral premix for 9 weeks. A basal diet with fish meal ($40\%$), meat meal ($9\%$), soybean meal ($5\%$), corngluten meal ($3\%$), and leather meal ($3\%$) as protein sources were included. Weight gain in fish fed diets deleted Ca, Zn, K, or Se was lower than that of control diet ( P<0.05). Daily feed intake, condition factor, hepatosomatic index and liver chemical composition were not affected by dietary mineral premixes (P>0.05). Apparent skeletal deformities were not observed in the diets deleted each mineral, The data obtained in this study indicate that each of the Ca, Zn, K, or Se should be added in the diet contained $40\%$ fish meal for normal growth of Korean rockfish.

  • PDF

Changes in quality characteristics of sliced garlic with different freezing conditions during storage (냉동조건에 따른 편마늘의 냉동저장 중 품질변화)

  • Kim, Seok-Young;Kim, Hee-Sun;Kim, Jin-Se;Han, Gwi-Jung
    • Food Science and Preservation
    • /
    • v.24 no.6
    • /
    • pp.746-757
    • /
    • 2017
  • This study was performed to evaluate the effect of different freezing conditions and storage periods on physicochemical and microbial characteristics of garlic. Garlics were washed, dried, sliced to 0.3 cm then packed in LDPE+LLDPE film bags. They were treated with still-air freezing at $-20^{\circ}C$ (SAF20), $-40^{\circ}C$ (SAF40) and immersed-liquid freezing at $-40^{\circ}C$ (ILF40). Frozen garlics were stored under frozen storage conditions for 7 months at $-20^{\circ}C$ and quality characteristics were measured monthly during the frozen storage. Freezing rate of garlic was the fastest in ILF 40 (10 min), SAF40 (40 min) and SAF20 (1,600 min) sequentially. In ILF40, drip loss, cutting force, total aerobic bacteria count and pH were the lowest, whereas pyruvic acid and allicin content were the highest (p<0.05) during frozen storage, these results were the most similar characteristics with the fresh garlic. During frozen storage, drip loss, color difference and total organic acid content were significantly fluctuated in SAF20 (p<0.05), while they were not changed in ILF40. Overall, total aerobic bacteria count and pH decreased, cutting force, pyruvic acid and allicin content remained unchanged in all groups. In conclusion, the optimal freezing conditions for garlic with the least quality changes was considered to be ILF40 (immersed liquid freezing), keeping quality characteristics up to 7 months by freezing storage.

Validation of the Korean Version of the Trauma Symptom Checklist-40 among Psychiatric Outpatients (정신건강의학과 외래환자 대상 한국판 외상 증상 체크리스트(Trauma Symptom Checklist-40)의 타당도 연구)

  • Park, Jin;Kim, Daeho;Kim, Eunkyung;Kim, Seokhyun;Yun, Mirim
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.26 no.1
    • /
    • pp.35-43
    • /
    • 2018
  • Objectives : Effects of multiple trauma are complex and extend beyond core PTSD symptoms. However, few psychological instruments for trauma assessment address this issue of symptom complexity. The Trauma Symptom Checklist-40 (TSC-40) is a self-report scale that assesses wide range of symptoms associated with childhood or adult traumatic experience. The purpose of the present study was to evaluate the validity of the Korean Version of the TSC-40 in a sample of psychiatric outpatients. Methods : Data of 367 treatment-seeking patients with DSM-IV diagnoses were obtained from an outpatient department of psychiatric unit at a university hospital. The diagnoses were anxiety disorder, posttraumatic stress disorder, depressive disorder, adjustment disorder and others. Included in the psychometric data were the TSC-40, the Life events checklist, the Impact of Event Scale-Revised, the Zung's Self-report Depression Scale, and the Zung's Self-report Anxiety Scale. Cronbach's ${\alpha}$ for internal consistency were calculated. Convergent and concurrent validity was approached with correlation between the TSC-40 and other scales (PTSD, anxiety and depression). Results : Exploratory factor analysis of the Korean Version of TSC-40 extracted seven-factor structure accounted for 59.55% of total variance that was contextually similar to a six-factor structure and five-factor structure of the original English version. The Korean Version of TSC-40 demonstrated a high level of internal consistency. (Cronbach's ${\alpha}=0.94$) and good concurrent and convergent validity with another PTSD scale and anxiety and depression scales. Conclusions : Excellent construct validity of The Korean Version of TSC-40 was proved in this study. And subtle difference in the factor structure may reflect the cultural issues and the sample characteristics such as heterogeneous clinical population (including non-trauma related disorders) and outpatient status. Overall, this study demonstrated that the Korean version of TSC-40 is psychometrically sound and can be used for Korean clinical population.