• Childhood Kidney Diseases
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• v.4 no.1
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• pp.11-16
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• 2000

Purpose. Urinary calcium excretion using a 24-hr urine colledtion has been used for the diagnosis of hypercalciuria up to now. But It takes a lot of time and costs much. We have investigated on a more simple method for screening of hypercalciuria in children. Methods: We had retrospectively analyzed sodium, potassium, calcium and creatinine in spot urine of eighty-four patients with urinary symptoms from May 1998 to July 1998 in Korea university Guro hospital and compared the urinary Ca/Cr ratio with the Nin ratio. Using a urinary Nan ratio >2.68 as a cutoff value in predicting the occurrence of hypercalciuria, we measured its sensitivity, specificity, positive predictive value and the negative predictive value. Results: A direct relationship was found between urinary Na/K and Ca/Cr ratio (r=0.496, P<0.001, Ca/Cr : Na/K x 0.0167+0.061). Using a urinary Na/K ratio >2.68 as a cutoff value in predicting the occurrence of hypercalciuria, its sensitivity was found to be $100\%$ and its specificity $54.5\%$. The positive predictive value was $37.5\%$ and the negative predictive value $100\%$. Conclusions : Spot urine Na/K ratio is a valuable test for the screening of hypercalciuria in children.

• Korean Journal of Community Nutrition
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• v.1 no.1
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• pp.71-78
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• 1996

This study was conducted to compare the dietary factors which influence on the bone status of 28 women in urban and 30 women in rural area. Urinary excretion of hydroxyproline(Hpr) and Calcium(Ca) were measured as biological markers of bone resorption. Mean daily intake levels of total protein, animal protein, total calcium, calcium, calcium from milk and milk products, animal calcium, Ca / P ratio by 24 hr recall method were significantly higher in urban women. However, mean daily sodium(Na) intake levels were not significantly different between two groups. Ca Index score and Na Index score by food frequency methods were also significantly higher in urban than in rural subjects. While urinary Ca excretion elves of two groups were similar, Na excretion levels were significantly higher in rural women. Mean urniary levels of Ca / creatinine(cr) and Hpr / cr as bone status index were within normal range and not significantly different between two groups. However, prevalence of poor bone status as assessed by hydroxyproline was higher in rural women. Na Index, urinary Ca excretion and Ca / cr ratio were significantly correlated with bone status(Hpr / cr) in urban women, while only age was related to bone status in rural women. These demonstrated that high Na intake results in increased urinary excretion of Na and Ca and could cause bone resorption. Multiple regression analysis indicated that Na Index score and age have greater effect than other variables in urban women and only age has greater effect in rural women.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.31-31
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• 2008

복합 싸이클 시험 모니터링을 통해 NaCl, $CaCl_2$ 제설염 환경에서 11 % Cr, 17 % Cr 페라이트 스테인리스강의 외면부식특성을 조사하고자 하였다. 용액 내 NaCl 및 $CaCl_2$의 농도가 증가함에 따라 용액의 pH가 떨어졌으며, $CaCl_2$의 농도증가에 따른 산성화도가 NaCl에 비해 크게 나타났다. 염수분무-건조-습윤 과정의 반복으로 구성되어 있는 복합싸이클 시험 중 소재의 표면상태 변화를 모니터링 한 결과, 건조 과정 중에 공식이 시작되며, NaCl 환경의 경우엔 습윤과정 중에 $CaCl_2$ 환경의 경우엔 건조 중에 공식성장이 주로 이루어지는 것으로 확인되었다.

• 한국전기화학회:학술대회논문집
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• 2005.04a
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• pp.66-66
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• 2005

• Journal of the Korean Magnetics Society
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• v.17 no.1
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• pp.14-17
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• 2007

Magnetic properties of transition metal doped $La_{0.5}Ca_{0.5}(Mn_{0.98}TM_{0.02})O_3$(TM=Cr and Ti) are studied. The samples are synthesized by the conventional solid-state method. Using vibrating sample magnetometer magnetization-temperature measurement were carried out with zero field cooling and field cooling at 50 Oe. Cr-doped sample shows cluster or spin glass like behavior while Ti doped does not. Curie temperature obtained were decreased from that of LCMO(245.5 K). Curie temperatures of Cr-doped and Ti-doped samples are 235.5 K and 232.7 K, respectively. The temperature-dependent coercivity $H_c(T)$ was also measured. The coercive force continuously decreases with the substitution of Cr and Ti, The result can be understood in terms of the interaction between defect and domain wall.

• Korean Journal of Materials Research
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• v.10 no.8
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• pp.540-544
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• 2000

The effect of atmospheric annearling on the densification and electrical poperty of the Ca-doped $YCrO_3$were investigated. In order to study the densification and elecrical properties of $Y_{0.7}Ca_{0.3}CrO3$ the sample sintered at $1700^{\circ}C$ for 12hrs were subsequently annealed at $1400^{\circ}C$ under various atmospheres($O_2$, Air, $N_2$)as a function of time. The density of $Y_{0.7}Ca_{0.3}CrO3$ was $4.5/cm^3$ before annealing. Under the $N_2$ annealingm the bulk density of $Y_{0.7}Ca_{0.3}CrO3$ was increased to $4.9g/cm^3$ at 24hrs and then remained unchanged at 48hrs. When $Y_{0.7}Ca_{0.3}CrO3$nwas annealing at $1400^{\circ}C$ for 12hrs and 24hrs under $O_2$ activation energies were about 0.16eV at 12hrs and 24hrs, and showed 0.167eV below 400K, and 0.24eV over 400K at 48hrs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.4
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• pp.592-597
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• 2010

Cinnamomi Ramulus is one of the medicinal plants that have been used to improve various diseases caused by insufficient blood circulation. This study was performed for the investigation of vasodilation efficacy ethanol extract of Cinnamomi Ramulus (CR). CR exhibited vascular relaxation against phenylephrine (PE, $10^{-6}M$)-, KCl- and NaF-induced contraction in rat thoracic aorta. In addition, its relaxation was endothelium-independent. Treatment of potassium channel blockers such as gilbenclamide (Gli, $10^{-5}M$), tetraethylammonium (TEA, 1 mM) and 4-aminopyridine (4-AP, 0.2 mM) did not effect on the relaxation of CR. The relaxant effects were also not inhibited by pre-treatment of rat aorta with L-NAME ($10^{-4}M$), methylene blue ($10^{-5}M$), indomethacin ($10^{-5}M$), and atropine ($10^{-6}M$). However, nifedipine ($10^{-5}M$), L-type $Ca^{2+}$ channel blocker, in part attenuated the relaxation of CR ($0.2\;mg/m{\ell}$), but SK&F96365 ($3{\times}10^{-5}M$), receptor activated $Ca^{2+}$ channel blocker and 2-APB ($10^{-4}M$), store operated $Ca^{2+}$ channel blocker did not affact dilation of CR. These findings suggest that the endothelium-independent relaxation effect of CR is partly related with inhibition of $Ca^{2+}$ influx via voltage dependent $Ca^{2+}$ channel.

• Archives of Pharmacal Research
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• v.29 no.11
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• pp.990-997
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• 2006

Sarcococca saligna is a shrub that is traditionally used for its medicinal properties in Pakistan. In this study we report the cardio-suppressant, vasodilator and tracheal relaxant activities of the aqueous-methanolic extract (Ss.Cr) of the plant. Ss.Cr, that tested positive for the presence of saponins, flavonoids, tannins, phenols, and alkaloids, exhibited a dose-dependent (0.3-5 mg/mL) negative inotropic and chronotropic effect on the isolated guinea-pig atrium which was resistant to atropine ($1\;{\mu}M$) and aminophylline ($10\;{\mu}M$) pretreatment. In rabbit thoracic aorta, Ss.Cr dose-dependently (0.1-3 mg/mL) relaxed the high $K^{+}$ (80 mM) and phenylephrine ($PE,\;1\;{\mu}M$)-induced contractions, indicating a possible $Ca^{++}$ channel blocking (CCB) effect. When tested against PE ($1\;{\mu}M$) control peaks in normal $Ca^{++}\;and\;Ca^{++}$-free Kreb's solution, Ss.Cr exhibited dose-dependent (0.1-3 mg/mL) inhibition, being more potent in relaxing the PE responses in $Ca^{++}$-free Kreb's solution, thus indicating specific blockade of $Ca^{++}$ release from the intracellular stores. Ss.Cr also relaxed the agonist-induced contractions in: a) rat aorta irrespective of the presence of endothelium or nitric oxide synthase inhibitor L-NAME and b) rabbit and guinea-pig tracheal strips. The data shows that Ss.Cr possesses possible $Ca^{++}$ channel blocking activity which might be responsible for its observed cardio-suppressant, vasodilator and tracheal relaxant effects though more tests are required to confirm this $Ca^{++}$ channel blocking effect.

• Journal of the Korean Ceramic Society
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• v.46 no.4
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• pp.405-412
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• 2009

In high temperature ceramic glazes, a stable range of pink-red colors that produced $Cr_2O_3-SnO_2-CaO-SiO_2$ pigments were factored by Cassiterite($SnO_2$) and Malayaite($CaSnSiO_5$) by $Cr_2O_3$. The experiment examined the influence of $CrCl_3$, a Sn-Cr substitution added with a mineralizer ($H_3BO_3$), as a chromophore in pigments. The experiment also studied the effect of $H_3BO_3$ (2 wt%) when added to malayaite($CaSnSiO_5$) to see if the crystalline reaction will increase. $Cr_2O_3$ was also substituted with $CrCl_3$ in order to prove how much influence $CrCl_3$ had on the $H_3BO_3$. Malayaite and cassiterite were the basic compound materials and the experiment was conducted both with and without mineralizers (2 wt% of $H_3BO_3$). Each compound was synthesized at 800, 1000, 1200, 1300, 1400, $1500^{\circ}C$ for 2 h. Synthesized pigments were analyzed by XRD, FT-IR and UV-Vis. The temperature variation produced two crystal phases that showed the different engaging effects of Cr oxidation. $CrCl_3$ produced a better effect on the malayaite crystal phase, resulting in a more defined pigmentation of the pink-red coloration compared to $Cr_2O_3$.

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1135-1141
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• 2008

The $La_{1-x}(Ca\;or\;Sr)xCrO_3$(x=0 and 0.25) interconnect materials for high temperature electrolysis of steam were investigated in views of sinterability and electrical conductivity. $LaCrO_3$, $La_{0.75}Ca_{0.25}CrO_3$ (LCC), and $La_{0.75}Sr_{0.25}CrO_3$ (LSC) powders were synthesized by coprecipitation method. Crystal structure was confirmed by X-ray diffraction (XRD). The sintering characteristics were analyzed by relative density and scanning electron microscopy. The electrical conductivity was measured by a DC four probe method. From the analyses of relative densities, it was found that the doped $LaCrO_3$ showed better sinterability than $LaCrO_3$ and the those sinterability increased with decrease of those particle sizes. The XRD results at different sintering temperatures for LCC and LSC revealed that the sinterability is closely related to the second phase transformation, that is, the second phase melting above $1,300^{\circ}C$ for LCC and $1,400^{\circ}C$ for LSC significantly promotes the sinterability. In case of electrical conductivities of LCC and LSC, which had a similar relative density, LCC showed better electrical conductivity than LSC.