• 생물환경조절학회지
• /
• 제19권4호
• /
• pp.387-391
• /
• 2010

본 연구는 우리나라에서 가장 많이 재배되고 있는 체리 '좌등금' 품종에 항지베렐린계 생장억제제인 Prohexadione-Calacium과 Paclobutrazol을 이용하여 체리의 신초생장을 억제하여 효율적인 생산성을 높이고 과실품질을 향상시키기 위한 기초 자료를 얻고자 시험을 한 결과를 요약하면 다음과 같다. 결실수에 대한 Prohexadione-Calacium을 150, 200 및 $250mg{\cdot}L^{-1}$ 농도로 각각 정단부에 처리 후 신초의 생장량을 측정한 결과 모든 처리구에서 무처리에 비해 신초 생장이 억제 되었으며, 처리 간에는 $200mg{\cdot}L^{-1}$에서 억제효과가 가장 높았다. 또한 처리구 모두 엽록소 a와 b 함량이 증가되었거나 증가되는 경향을 보였다. 그러나 과실의 특성(과실크기, 당도, 산함량 및 경도)은 무처리와 차이가 없었다. 유목에 대한 Prohexadione-Calcium 수관살포(3회)와 Paclobutrazol 토양관주(1회) 처리한 후 신초 생장반응은 두 처리 모두 무처리에 비하여 높은 신초생장 억제를 보였고 약제간에는 Prohexadione-Calcium의 신초생장 억제효과가 더 높았으며 Paclobutrazol 토양관주 처리에서는 간주 생장이 억제되는 경향을 보였다. 또한 Prohexadione-Calcium과 Paclobutrazol 처리 모두 절간 수의 차이가 없었으며, 무처리에 비하여 엽면적이 억제 되었고, 엽록소 a 와 b의 함량 모두 높은 결과를 보였으며 특히 Prohexadione-Calcium 처리구에서 엽록소 함량이 더욱 높고 잎의 두께가 두꺼웠다.

• 공학논문집
• /
• 제6권1호
• /
• pp.97-109
• /
• 2004

CaO의 첨가량에 따라 $CO_2$가스를 불어넣고 반응시간 변화에 따라 용매로 $C_2 H_5 OH$을 사용하여 에틸렌글리콜을 첨가한 CaO-$C_2 H_5 OH$-$CO_2$계의 기.액반응으로부터 비정질 $CaCO_3$의 합성과 결정구조를 전기전도도, X-선회절 및 주사전자현미경으로 조사하였다. 이 반응에서 900ml의 $C_2 H_5 OH$에 에틸렌글리콜 100ml를 첨가하고 CaO의 양을 10~40g으로 하여 $CO_2$가스를 1$\ell$/min의 유속으로 흡입시켜 얻은 합성분말의 겔형 물질을 신속히 여과, 감압하의 $60^{\circ}C$에서 건조하여 1${\mu}m$이하의 구형 vaterite상과 무정형인 비정질 $CaCO_3$을 얻었다. 그리고 비정질 $CaCO_3$의 일부는 중간생성물로서 연쇄형 calcite로 변화하는 것을 알 수 있었고 침강성 $CaCO_3$의 생성보다 먼저 초기 반응생성물은 비정질 $CaCO_3$이었고 이 경우 생성역역은 pH 7-9의 범위로 상당한 영향을 준다. 또한 비정질 $CaCO_3$은 용액 속에서 불안정하여 용해반응으로 인해서 결국 calcite로 결정화한다. 특히 비정질 $CaCO_3$은 CaO-$C_2 H_5 OH$-$CO_2$계의 반응에 의해서 침강되어 생성되거나 또는 gel상으로 된다.

• Molecules and Cells
• /
• 제24권2호
• /
• pp.276-282
• /
• 2007

Protein phosphorylation is one of the major mechanisms by which eukaryotic cells transduce extracellular signals into intracellular responses. Calcium/calmodulin ($Ca^{2+}/CaM$)-dependent protein phosphorylation has been implicated in various cellular processes, yet little is known about $Ca^{2+}/CaM$-dependent protein kinases (CaMKs) in plants. From an Arabidopsis expression library screen using a horseradish peroxidase-conjugated soybean calmodulin isoform (SCaM-1) as a probe, we isolated a full-length cDNA clone that encodes AtCK (Arabidopsis thaliana calcium/calmodulin-dependent protein kinase). The predicted structure of AtCK contains a serine/threonine protein kinase catalytic domain followed by a putative calmodulin-binding domain and a putative $Ca^{2+}$-binding domain. Recombinant AtCK was expressed in E. coli and bound to calmodulin in a $Ca^{2+}$-dependent manner. The ability of CaM to bind to AtCK was confirmed by gel mobility shift and competition assays. AtCK exhibited its highest levels of autophosphorylation in the presence of 3 mM $Mn^{2+}$. The phosphorylation of myelin basic protein (MBP) by AtCK was enhanced when AtCK was under the control of calcium-bound CaM, as previously observed for other $Ca^{2+}/CaM$-dependent protein kinases. In contrast to maize and tobacco CCaMKs (calcium and $Ca^{2+}/CaM$-dependent protein kinase), increasing the concentration of calmodulin to more than $3{\mu}M$ suppressed the phosphorylation activity of AtCK. Taken together our results indicate that AtCK is a novel Arabidopsis $Ca^{2+}/CaM$-dependent protein kinase which is presumably involved in CaM-mediated signaling.

• Journal of Nutrition and Health
• /
• 제24권1호
• /
• pp.30-39
• /
• 1991

This study was designed to investigate the effects of dietary calcium. serum estrogen level and physical activity on the bone status of 116 healthy elderly women living in urban area. Current calcium intake was assessed by convenient method(refered to as Ca intake) and calcium containing food frequency method(refered to as Ca index) Daily activity record was used for the estimation of physical activity level, and serum estrogen level was measured from fasting blood of subjects. The rate of bone resorption was evaluated by the determination of hydroxyproline(Hpr) in fasting urine with correction for creatinine excretion. The results of this study are summarized as follows : 1) Average daily Ca intake of subjects was 621.4$\pm$155.8mg, which is above the Korean recommended dietary allowances. However 44.8% of the subjects consumed Ca below RDA level. Ca index score was significantly correlated with the bone status(P<0.05), Ca intake did not show significant correlation with the bone status although a positive trend of influence was evident. 2) Average serum estrogen level of subjects was 18.7$\pm$9.8pg Contrary to our anticipation. estrogen level did not show any significant relation to age and bone status. 3) Daily physical activity was classified into four categories by activity intensity : sedentary. moderate, active and severe. The average physical activity of subjects belong to moderate level. and the bone status was significantly related to the physical activity(P<0.01) 4) Among other influential factors such as age, pocket-money. family type. drinking, smoking and BMI, there was a significant difference between bone status and BMI(P<0.05). 5) Multiple regression analysis of variables showed that physical activity has greater effect than other variables when the entire subjects were taken into account. However. eliminating the subjects whose bone status rated as excellent(Hpr/cr<0.009), Ca index showed higher correlation than physical activity. These results have demonstrated that dietary calcium intake is the primary important factor for keeping good bone health and that bone status of subjects with a sufficient calcium intake is affected by various factors such as physical activity, age, smoking. BMI and others.

• The Korean Journal of Physiology and Pharmacology
• /
• 제2권4호
• /
• pp.419-425
• /
• 1998

To clarify the effect of extracellular ATP in cultured C6 glioma cells, ATP-induced cytosolic free calcium ($[Ca^{2+}]_i$) mobilization and cell proliferation were investigated. ATP-induced $[Ca^{2+}]_i$ increased in a dose-dependent manner $(10^{-7}\;M{\sim}10^{-3}\;M)$. ATP-induced $[Ca^{2+}]_i$ increases were slightly slowed in extracellular calcium-free conditions especially in sustained phase. ATP-induced $[Ca^{2+}]_i$ increment was also inhibited by the pretreatment of U73122, a phospholipase C (PLC) inhibitor, in a time-dependent manner. Suramin, a putative $P_{2Y}$ receptor antagonist, dose-dependently weakened ATP-induced $[Ca^{2+}]_i$ mobilization. Significant increases in cell proliferation were observed at 2, 3, and 4 days after ATP was added. Stimulated cell proliferation was also observed with adenosine at days 2 and 3. This cell proliferation was significantly inhibited by the treatment with suramin. Ionomycin also stimulated cell proliferation in a concentration-dependent manner. In conclusion, we suggest that extracellular ATP stimulates C6 glioma cell proliferation via intracellular free calcium mobilization mediated by purinoceptor.

• 대한화학회지
• /
• 제57권3호
• /
• pp.365-369
• /
• 2013

With the wide application of ASP (alkaline-surfactant-polymer) flooding, the scaling becomes more and more serious, which is harmful to the oilfield and environment. In order to investigate the effects of HPAM on calcium carbonate crystallization, the crystallization behaviors of $CaCO_3$ in HPAM (Hydrolyzed polyacrylamide) solutions were studied and the composition and morphology of $CaCO_3$ crystal were investigated in different concentrations of polyacrylamide solutions. The crystal forms and morphologies of $CaCO_3$ were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The results show that the crystallization of $CaCO_3$ is strongly influenced by the HPAM. The paper analyzed the internal cause, and the results show: The reasons leading to the change of morphology are carboxyl groups in polyacrylamide molecule and $Ca^{2+}$ in solution form chelates by coordination bond. And the chelates are adsorbed on the calcium hydroxide surfaces of solid-liquid interfaces so as to change the formation rate of calcium carbonate crystal nucleus. The research provides a reliable basis for the mechanism research of the scaling problem in the oil extraction process of ASP flooding and the adoption of scale inhibition and scale inhibitor.

• Nutritional Sciences
• /
• 제5권3호
• /
• pp.155-160
• /
• 2002

The purpose of this study was to investigate the effects of micronutrient supplementation on the growth of preschool children in China. A double-blind, placebo-controlled trial was conducted on 156 growth retarded preschool children who were randomly assigned to the following five groups : supplemental control (S-control; n=28); zinc supplementation (＋Zn; 3.5mg Zn/day, n=34); zinc and calcium supplementation (＋ZnCa; 3.5mg Zn ＋ 250mg Ca/day, n=37); zinc, calcium and vitamin A supplementation (＋ZnCaVA; 3.5mgZn ＋ 250mgCa ＋ 200gVA/day, n=28); and calcium and vitamin A supplementation (＋CaVA; 250mgCa ＋ 200gVA/day, n=29). Another 34 children of normal height were selected as a normal control (N-control). Supplementation continued for twelve months. After supplementation, the height gains in the ＋Zn group (7.84cm per year) and the ＋ZnCa group (7.70 cm per year) were significantly higher than that in the S-control group (6.74 cm per year, P＜0.05). The weight gain in the ＋ZnCaVA group (2.55kg per year) and the ＋CaVA group (2.57 kg per year) was also significantly higher than that in the S-control group (2.19 kg per year, P＜0.05). The average number of days of illness in each group taking supplements was lower than that in the S-control group (13 days per year compared with 23 days per year). No significant differences in bone maturity were observed between the groups. In conclusion, in this study Zinc and Zinc ＋ Calcium supplementation improved the height gain, and vitamin A improved the weight gain, in growth retarded preschool children, but these supplements did not affect the maturity of bone. Micronutrient supplementation also lowered the morbidity of these children.

• Biomolecules & Therapeutics
• /
• 제26권5호
• /
• pp.439-445
• /
• 2018

T-type calcium channels are low voltage-activated calcium channels that evoke small and transient calcium currents. Recently, T-type calcium channels have been implicated in neurodevelopmental disorders such as autism spectrum disorder and neural tube defects. However, their function during embryonic development is largely unknown. Here, we investigated the function and expression of T-type calcium channels in embryonic neural progenitor cells (NPCs). First, we compared the expression of T-type calcium channel subtypes (CaV3.1, 3.2, and 3.3) in NPCs and differentiated neural cells (neurons and astrocytes). We detected all subtypes in neurons but not in astrocytes. In NPCs, CaV3.1 was the dominant subtype, whereas CaV3.2 was weakly expressed, and CaV3.3 was not detected. Next, we determined CaV3.1 expression levels in the cortex during early brain development. Expression levels of CaV3.1 in the embryonic period were transiently decreased during the perinatal period and increased at postnatal day 11. We then pharmacologically blocked T-type calcium channels to determine the effects in neuronal cells. The blockade of T-type calcium channels reduced cell viability, and induced apoptotic cell death in NPCs but not in differentiated astrocytes. Furthermore, blocking T-type calcium channels rapidly reduced AKT-phosphorylation (Ser473) and $GSK3{\beta}$-phosphorylation (Ser9). Our results suggest that T-type calcium channels play essential roles in maintaining NPC viability, and T-type calcium channel blockers are toxic to embryonic neural cells, and may potentially be responsible for neurodevelopmental disorders.

• The Korean Journal of Physiology and Pharmacology
• /
• 제20권5호
• /
• pp.449-457
• /
• 2016

N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though $Ca^{2+}$ signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ($[Ca^{2+}]_i$) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on $[Ca^{2+}]_i$ in human neutrophils. We observed that NAC ($1{\mu}M{\sim}1mM$) and cysteine ($10{\mu}M{\sim}1mM$) increased $[Ca^{2+}]_i$ in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in $[Ca^{2+}]_i$ in human neutrophils was observed. In $Ca^{2+}$-free buffer, NAC- and cysteine-induced $[Ca^{2+}]_i$ increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in $[Ca^{2+}]_i$ in human neutrophils occur through $Ca^{2+}$ influx. NAC- and cysteine-induced $[Ca^{2+}]_i$ increase was effectively inhibited by calcium channel inhibitors SKF96365 ($10{\mu}m$) and ruthenium red ($20{\mu}m$). In $Na^+$-free HEPES, both NAC and cysteine induced a marked increase in $[Ca^{2+}]_i$ in human neutrophils, arguing against the possibility that $Na^+$-dependent intracellular uptake of NAC and cysteine is necessary for their $[Ca^{2+}]_i$ increasing activity. Our results show that NAC and cysteine induce $[Ca^{2+}]_i$ increase through $Ca^{2+}$ influx in human neutrophils via SKF96365- and ruthenium red-dependent way.

• Journal of Nutrition and Health
• /
• 제30권5호
• /
• pp.499-505
• /
• 1997

This study was conducted to investigate the effect of various types of calcium sources on calcium metabolism. Sprague-Dawley male rate weighing approximately 82g were divided into 6 groups and fed experimental diets containing about 0.2% calcium for 4 weeks. Perilla leaves, dried sea mustard, mulberry leaves, loach, skim milk powder, and CaCO3 were used as calcium sources for this study. Food intake of experimental groups showed no significant difference from that of control group, but food efficiency ratio were higher in group fed loach as a calcium source. Apparent calcium absorption from perilla leaves, and skim milk powder groups as good as that in CaCO group. Femur length showed no significant difference among exjerimental groups with different calcium sources. The breaking force of bone was higher in loach and dried sea mustard groups. Weight, ash weight, and calcium content of the femur were higher in the loach diet group than in the others. Thus, calcium from not only skim milk powder but also perilla leaves, dried sea mustard, mulberry leaves, and loach appears readily available and all of these can be recommended as calcium sources.