• Title/Summary/Keyword: Effective concentration

Search Result 5,509, Processing Time 0.037 seconds

Studies on Solvent Extraction and Analytical Application of Metal-dithizone Complexes(I). Separation and Determination of Trace Heavy Metals in Urine (Dithizone 금속착물의 용매추출 및 분석적 응용(제1보). 뇨중 흔적량 중금속 원소의 분리 정량)

  • Jeon, Moon-Kyo;Choi, Jong-Moon;Kim, Young-Sang
    • Analytical Science and Technology
    • /
    • v.9 no.4
    • /
    • pp.336-344
    • /
    • 1996
  • The extraction of trace cobalt, copper, nickel, cadmium, lead and zinc in urine samples of organic and alkali metal matrix into chloroform by the complex with a dithizone was studied for graphite furnace AAS determination. Various experimental conditions such as the pretreatment of urine, the pH of sample solution, and dithizone concentration in a solvent were optimized for the effective extraction, and some essential conditions were also studied for the back-extraction and digestion as well. All organic materials in 100 mL urine were destructed by the digestion with conc. $HNO_3$ 30 mL and 30% $H_2O_2$ 50 mL. Here, $H_2O_2$ was added dropwise with each 5.0 mL, serially. Analytes were extracted into 15.0 mL chloroform of 0.1% dithizone from the digested urine at pH 8.0 by shaking for 90 minutes. The pH was adjusted with a commercial buffer solution. Among analytes, cadmium, lead and zinc were back-extracted to 10.00 mL of 0.2 M $HNO_3$ from the solvent for the determination, and after the organic solvent was evaporated, others were dissolved with $HNO_3-H_2O_2$ and diluted to 10.00 mL with a deionized water. Synthetic digested urines were used to obtain optimum conditions and to plot calibration-eurves. Average recoveries of 77 to 109% for each element were obtained in sample solutions in which given amounts of analytes were added, and detection limits were Cd 0.09, Pb 0.59, Zn 0.18, Co 0.24, Cu 1.3 and Ni 1.7 ng/mL, respectively. It was concluded that this method could be applied for the determination of heavy elements in urine samples without any interferences of organic materials and major alkaline elements.

  • PDF

Effects of Total Mixed Rations on Ruminal Characteristics, Digestibility and Beef Production of Hanwoo Steers (섬유질배합사료 급여가 비육후기 거세한우의 반추위 발효성상, 소화율 및 산육성에 미치는 영향)

  • Kim, K.H.;Kim, K.S.;Lee, S.C.;Oh, Y.G.;Chung, C.S.;Kim, K.J.
    • Journal of Animal Science and Technology
    • /
    • v.45 no.3
    • /
    • pp.387-396
    • /
    • 2003
  • This experiment was carried out to compare the effects of feeding commercial formula feed and rice straw separately (control) versus a total mixed ration (TMR) on productivity of Hanwoo steers in late stage of fattening and on ruminal fermentation characteristics and digestibilities. Ruminal digesta from the cannulated cattle were sampled at 0, 1, 2, 3, 5, 8 hour after feeding. The steers fed TMR consumed 7.4kg per day and there was no difference between feeding systems. Daily weight gain was not significantly (P>0.05) between feeding systems, however, TMR group showed lower daily gain than control group. The amount of feed consumption per kg weight gain was higher in TMR group than control group (10.5kg and 9.7kg, respectively), resulting in a greater efficiency of feed utilization for gain. In the result of appearance rates of quality grade A were 33% higher for TMR group than those in control group. Appearance rates of grade 1 showed 56% and 75% when fed the control and TMR, respectively. Digestibilities of dry matter, crude protein, crude fiber and gross energy for TMR treatment were significantly higher (P<0.01) than those of control. Prior to feeding (0 h) and each subsequent hour, the TMR resulted in higher rumen pH (P<0.05) when compared with control ration. The concentration of NH3-N for TMR treatment maintained at higher level up to 8hr after feeding, especially increased up to 28.2mg/$d\ell$ during 1-2 hour which was two times (P<0.05) more than control. The amount of total VFA showed same trends between feeding systems. However, the ratios of branched chained fatty acid such as iso-butyric acid and iso-valeric acid for TMR treatment were significantly(P<0.01) higher than control for 3-5hr. Results showed that TMR in these trials is effective feeding system for fattening Hanwoo steers in the respect of ruminal characteristics, total tract digestibility and productivities.

Therapeutic comparison between low-dose sustained-release theophylline dry syrup and capsule in children with mild persistent asthma (유소아 경증 지속성 천식에서 저용량 서방형 테오필린 건조시럽과 캡슐 제형의 치료 효과 비교)

  • Lee, Hyun Seung;Lee, Hae Kyung;Kwon, Hi Jeong;Kim, Jeong Hee;Rha, Yeong Ho;Kim, Jin Tack;Kim, Young Ho;Lee, Hae Rhan;Pyun, Bok Yang
    • Clinical and Experimental Pediatrics
    • /
    • v.50 no.3
    • /
    • pp.284-291
    • /
    • 2007
  • Purpose : Theophylline has recently been reported to have concurrent anti-inflammatory effects at low therapeutic plasma concentrations which are below the doses at which significants, clinically useful bronchodilatation is evident. Sustained-release formulation in capsule and dry syrup forms were developed to reduce its adverse effects and improve its clinical effects. We compared the therapeutic effects of theophylline dry syrup and capsules in children with mild asthma. Methods : Ninety children with mild asthma were randomized to receive either theophylline dry syrup (n=44) or theophylline capsules (n=46); 4 mg per kilogram of body weight, twice a day, for 12 weeks. Baseline and serial measurements of daytime and nighttime asthma symptom score were performed. Compliance scores, drug swallowing scores, and drug usability scores were measured every 4 weeks. Each scoring was rated on a scale of 0-4. Serum theophylline concentration were measured at 4 and at 12 weeks. To examine the anti-inflammatory effect of theophylline on asthma, Serum eosinophilic cationic protein as a marker of airway inflammation caused by eosinophil was measured 12 weeks pre- and post-administration. Results : The daytime and nighttime asthma symptom scores of the two groups after 4 weeks significantly improved over the baseline score. Daytime and nighttime asthma symptom scores in the dry syrup group were statistically lower at all time points except for the nighttime symptom scores at 4 weeks. Compliance scores, drug swallowing scores, and drug usability scores in the dry syrup group were significantly higher at the end time point. Only in the dry syrup group was the serum ECP at the end time point statistically lower than baseline. Conclusion : Low-dose sustained-release theophylline may be safe and effective in bronchial asthma and this effect may be mediated by its anti-inflammatory action mechanisms. Especially, when used in children with asthma, dry syrup formulation is recommended because of its higher compliance than capsule formulation.

The Vasodilating Mechanism of Atrial Natriuretic Peptide in 2-kidney 1 Clip Renovascular Hypertensive Rats (2-kidney 1 clip 신혈관성 고혈압흰쥐에서의 심방이뇨??????타이드의 혈관이완작용의 기전)

  • Jung, Jin-Young;Ahn, Young-Chul;Kim, Hun-Sik;Koh, Gou-Young;Ahn, Hee-Yul;Kim, Myung-Suk
    • The Korean Journal of Pharmacology
    • /
    • v.32 no.1
    • /
    • pp.51-56
    • /
    • 1996
  • The objectives of this study is to find out mechanism of vasodilating effects of ANP in 2K-1C renovascular hypertensive rat aorta and to compare with those of normotensive rat aorta. In 2K-1C renovascular hypertensive rat, average arterial blood pressure and plasma renin activity were higher than in normotensive rat. In 2K-1C renovascular hypertensive rat aorta, NE sensitivity was more increased and maximal contraction of aorta by NE was higher than those of normotensive rat aorta. ANP inhibited NE-induced contraction in both 2K-1C renovascular hypertensive and normotensive rat aorta, concentration-dependently. However, ANP was less effective for relaxing NE-induced contraction in 2K-1C renovascular hypertensive rat aorta than in normotensive rat aorta. ANP inhibited $^{45}Ca^{2+}$ uptake induced by NE in both 2K-1C renovascular hypertensive and normotensive rat aorta. From these results. inhibition of $Ca^{2+}$ influx may be one of the vasodilating mechanism of ANP in 2K-1C renovascular hypertensive rat aorta. Although the potency of ANP in relaxing NE-induced contractions was attenuated, the efficacy of ANP was not changed in 2K-1C renovascular hypertensive rat aorta compared with that of ANP in normotensive rat aorta. Abbreviations: ANP, Atrial natriuretic peptide; 2K-1C, 2-kidney 1 clip; NE, norepinephrine; SHR, Spontaneously hypertensive rat; DOC, Deoxycorticosterone; EDTA, Ethylenediaminetetra-acetic acid; PSS, Physiological salt solution; TRIS, tris(hydroxymethyl) aminomethane

  • PDF

Effect of Moutan Cortex Radicis on gene expression profile of differentiated PC12 rat cells oxidative-stressed with hydrogen peroxide (모단피의 PC12 cell 산화억제 효과 및 neuronal 유전자 발현 profile 분석에 대한 연구)

  • Kim Hyun Hee;Rho Sam Woong;Na Youn Gin;Bae Hyun Su;Shin Min Kyu;Kim Chung Suk;Hong Moo Chang
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.17 no.2
    • /
    • pp.529-541
    • /
    • 2003
  • Yukmijihwang-tang has been widely used as an and-aging herbal medicine for hundred years in Asian countries. Numerous studies show that Yukmijihwangtang has anti-oxidative effect both in vivo and in vitro. It has been reported that Moutan Cortex Radicis extract (MCR) was the most effective herb in Yukmijihwang-tang on undifferentiated PC12 cells upon oxidative-stressed with hydrogen peroxide. The purpose of this study is to; 1) evaluate the recovery of neuronal damage by assessing the anti-oxidant effect of MCR on PC12 cells differentiated with nerve growth factor (NGF), 2) identify candidate genes responsible for anti-oxidative effect on differentiated PC12 cells by oligonucleotide chip microarray. PC12 cells, which were differentiated by treating with NGF, were treated without or with hydrogen peroxide in the presence or absence of various concentration of MCR. Cell survival was determined by using MTS assay. Measurement of intracellular reactive oxygen species (ROS) generation was determined using the H2DCFDA assay The viability of cells treated with MCR was significantly recovered from stressed PC12 cell. In addition, wide rage of concentrations of MCR shows dose-dependent inhibitory effect on ROS production in oxidative-stressed cells. Total RNAs of cells without treatment(Control group), only treated with H₂O₂ (stressed group) and treated with both H₂O₂ and of MCR (MCR group) were isolated, and cDNAs was synthesized using oligoT7(dT) primer. The fragmented cRNAs, synthesized from cDNAs, were applied to Affymetrix GeneChip Rat Neurobiology U34 Array. mRNA of Calcium/calmodulin-dependent protein kinase II delta subunit(CaMKII), neuron glucose transporter (GLUT3) and myelin/oligodendrocyte glycoprotein(MOG) were downregulated in Stressed group comparing to Control group. P2X2-5 receptor (P2X2R-5), P2X2-4 receptor (P2X2R-4), c-fos, 25 kDa synaptosomal attachment protein(SNAP-25a) and GLUT3 were downregulated, whereas A2 adenosine receptor (A2AR), cathechol-O-methyltransferase(COMT), glucose transporter 1 (GLUT1), EST223333, heme oxygenase (HO), VGF, UI-R-CO-ja-a-07-0-Ul.s1 and macrophage migration inhibitory factor (MIF) were upregulated in MCA group comparing to Control group. Expression of Putative potassium channel subunit protein (ACK4), P2X2A-5, P2X2A-4, Interferon-gamma inducing factor isoform alpha precursor (IL-18α), EST199031, P2XR, P2X2 purinoceptor isoform e (P2X2R-e), Precursor interleukin 18 (IL-18) were downregulated, whereas MOO, EST223333, GLUT-1, MIF, Neuronatin alpha, UI-R-C0-ja-a-07-0-Ul.s1, A2. adenosine receptor, COMT, neuron-specific enolase (NSE), HO, VGF, A rat novel protein which is expressed with nerve injury (E12625) were upregulated in MCR group comparing to Stressed group. The results suggest that decreased viability and AOS production of PC12 cell by H₂O₂ may be, at lease, mediated by impaired glucose transporter expression. It is implicated that the MCR treatment protect PC12 cell from oxidative stress via following mechanisms; improving glucose transport into the cell, enhancing expression of anti-oxidative genes and protecting from dopamine cytotoxicity by increment of COMT and MIF expression. The list of differentially expressed genes may implicate further insight on the action and mechanism behind the anti-oxidative effects of herbal extract Moutan Cortex Radicis.

Filtration Characteristics of H2O-C6H12O6 Solution at Cell Membrane Model of Kidney which Irradiated by High Energy X-Ray (고에너지 엑스선을 조사한 신장의 세포막모델에서 포도당수용액 (H2O-C6H12O6)의 여과작용특성)

  • Ko, In-Ho;Yeo, Jin-Dong
    • Journal of the Korean Society of Radiology
    • /
    • v.14 no.2
    • /
    • pp.85-95
    • /
    • 2020
  • The filtration characteristics of H2O-C6H12O6 solution at cell membrane model in renal tubule which irradiated by high energy x-ray(linac 6MV) was investigated. The cell membrane model used in this experiment was a polysulfonated copolymerized membrane of m-phenylene-diamine(MPD) and trimesoyl chloride(TMC)-hexane. They were used to two cell membrane models(CM-1, CM-2). The cell membrane model composed of 0.5 wt% TMC-hexane solution(CM-2) had higher permeate flux(Jv) and rejection coefficient(R) than composed of 0.1 wt% TMC-hexane solution(CM-1). The permeate flux(Jv) and rejection coefficient(R) of H2O-C6H12O6 solution in two cell membrane models(CM-1, CM-2) were increased with increase of pressure drop and effective pressure difference. In this experiment range(pressure 1.5-4 MPa, temperature 36.5 ℃), permeate flux(Jv) of H2O solvent in irradiated membrane was found to be decreased about 20-30 times than non-irradiated membrane, permeate flux(Jv) and rejection coefficient(R) of H2O-C6H12O6 solution in irradiated membrane was found to be decreased about 2-13 times, about 4-6 times than non-irradiated membrane, respectively. The concentration increase of H2O-C6H12O6 solution at cell membrane model significantly was increased at rejection coefficient(R), was decreased at permeate flux(Jv). As the filtration of H2O-C6H12O6 solution in cell membrane model were abnormal, cell damages were appeared at cell.

Chronic Kidney Disease-mineral Bone Disorder and Active Vitamin D Analogs for Treating Severe Hyperparathyroidism in Children Receiving Chronic Peritoneal Dialysis (소아복막투석환자에서 CKD-MBD와 중증 부갑상샘 기능항진증에서 비타민 D 치료)

  • Kang, Eun Gu;Lee, Joo Hoon;Park, Young Seo
    • Childhood Kidney Diseases
    • /
    • v.18 no.2
    • /
    • pp.64-70
    • /
    • 2014
  • Purpose: The aims of this study were to assess the clinical and laboratory profiles of chronic kidney disease-mineral bone disorder (CKD-MBD) and to assess the effects of treatment of active vitamin D analogs on severe hyperparathyroidism (SHPT) in pediatric patients on chronic peritoneal dialysis. Methods: This is a retrospective study included 53 patients who had been undergoing dialysis for more than 1 year, between January 2003 and December 2012. Results: Even after treatment with phosphate binders and active vitamin D analogs, the $mean{\pm}standard$ deviation of the percentage of time during peritoneal dialysis that the patients' serum concentrations of phosphorus, corrected total calcium, and parathyroid hormone (PTH) fell within the Kidney Disease Outcomes Quality Initiative recommended ranges was $25.06{\pm}17.47%$, $53.30{\pm}23.03%$, and $11.52{\pm}9.51%$, respectively. Clinical symptoms or radiological signs of CKD-MBD were observed in 10 patients (18.9%). There were significant differences in percentage of time that the serum intact PTH concentration was outside of the recommended range between patients with and without symptoms or signs of CKD-MBD (below recommended range, $11.74{\pm}7.37%$ vs. $40.77{\pm}25.39%$, P <0.001; above the recommended range, $63.79{\pm}27.86%$ vs. $37.09{\pm}27.76%$, P =0.022). Of the 25 patients with SHPT, high-dose alfacalcidol treatment was required in 13 patients that controlled SHPT in 7 of these patients, without marked complications. Conclusion: Despite our efforts to manage CKD-MBD, patients' met the recommended ranges from relevant guidelines at a low frequency. The treatment of high-dose active vitamin D analogs was required in about half of the patients with SHPT and effective in about half of them.

Algicidal Characteristics of 1-Alkyl-3-Methylimidazolium Chloride Ionic Liquids to Several Fresh-water Algae (이온성 액체 1-alkyl-3-methylimidazolium chloride계 화합물의 담수조류에 대한 살조활성 특징)

  • Hwang, Hyun-Jin;Kim, Jae-Deog;Choi, Jung-Sup;Kim, Young-Wun;Kim, Jin-Seog
    • Korean Journal of Weed Science
    • /
    • v.30 no.3
    • /
    • pp.233-242
    • /
    • 2010
  • This study was conducted to know that if ionic liquids can be applicable as control agents of harmful algae in water-ecosystem and to find out problems caused by ionic liquid application. Firstly, the differential selectivity of various fresh-water algal species to several 1-alkyl-3-methylimidazolium chloride ionic liquids was investigated. There was a distinct differential response between alkyl chain lengths from butyl to dodecyl and towards the algal organisms : Generally algicidal activity was increased with increase of chain length and among the algae used in this study, Stephanodiscus hantzschii f. tenuis, Oscillatoria tenuis and Spirulina pratensis were most sensitive to 1-dodecyl-3-methylimidazolium chloride (MAIC12), next was Microcystis aeruginosa, and the others were relatively less sensitive to the chemical. The selectivity degree was about ten to twenty times based on the $EC_{80}$ (Effective concentration required for 80% growth inhibition). Secondly, an activity persistence of ionic liquids was investigated in natural mimic condition (using water bottle containing soil-sediments under the greenhouse condition). At the application of $1.0{\mu}g\;mL^{-1}$ of 1-octyl-3-methylimidazolium chloride (MAIC8), the algal growth did not occur at all until 6 days after treatment(DAT) and observed a only little growth at 9 DAT. But the algae grew rapidly after 9 DAT. So at 20 DAT, total chlorophylls was $264.4{\mu}g\;L^{-1}$ and the growth was inhibited by 58.2% compared to untreatment. On the other hand, MAIC12 also had a similar persistence pattern to MAIC8, showing nearly 5 times more activity than MAIC8. At 20 days after $0.2{\mu}g\;mL^{-1}$ application of MAIC12, that is, total chlorophylls was $251.2{\mu}g\;L^{-1}$ and the growth was inhibited by 55.2% compared to untreatment. In summary, 1-alkyl-3-methylimidazolium chloride ionic liquids is likely to be applicable for selective control of harmful algae as potent compounds having long lasting activity. However, the difficulty of degradation seems to be a limiting factor in an eco-friendly application of the compounds.

A Study on the Effective Controlling System of Radio-activity Ventilation (RI사용 의료기관의 효율적인 배기관리 방안)

  • Lee, Kyung-Jae;Lee, Jin-Hyung;Kim, Kyung-Hoon;Kwack, Dong-Woo;Jo, Hyun-Duck;Ko, Kil-Man;Park, Young-Jae;Lee, In-Won
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.12 no.1
    • /
    • pp.91-98
    • /
    • 2008
  • Purpose: Radio-isotopes (RI) use has been steadily developing due to industrial and technical development in the modern medical society. Particularly, popularization of domestic cyclotrons dramatically enable hospitals to produce and use diagnostic radio-isotopes. Generally, only specific facilities such as hospitals, research institutes, nuclear power plants and universities can use radio-isotopes, they are also responsible for ventilation system. The strength of radioactivity in the air is strongly regulated and controlled by korea atomic energy law in Korea Institue of Nuclear Safety (KINS), so that air radioactivity exposure can lead to environmental pollution surrounding places. In this study, we'd like to find out the investigation and the present condition of the controlled ventilation system in domestic hospitals by an emission standard from KINS, and try to reach an agreement about how to use the ventilation system. Result: Definition of filters, features and structures of pre-filters, hepa-filters, charcol filters, filter exchange procedures and precautions are explained. RI deflation concentration and filter exchange cycle have been presented as a standard prescribed in the rules of KINS. The Radiation Control Management System (RCMS) introduced by Seoul National University Bundang Hospital linking to digital pressure gauge with computer controller in another medical facilities were described in details. Conclusions: The system of medical facilities using RI has been remarkably developing in 21 century. Especially, radiation safety control system has also been grown rapidly into the subdivision, specialization, advanced technology along with international technical improvement. However, As far as current RI ventilation system is concerned, it has nothing better than doing in the past. Preferentially, to reinforce this, more sophisticated system with strict periodic filter exchange and exhaust air control guidance should be introduced by applying brilliant domestic information technology for RCMS and digital gauge method. From personal point of view as a radiation safety manager, I have provide with present problems and improvements. Futhermore, more improved guidance should be conducted.

  • PDF

Dry Matter Yield and Forage Quality at Mixture of Annual Legumes and Italian ryegrass on Paddy Field (논에서 이탈리안 라이그라스와 두과 사료작물 혼파에 따른 생산성 및 사료가치 비교)

  • Kim, Won-Ho;Kim, Ki-Young;Jung, Min-Woong;Ji, Hee-Chung;Lim, Young-Chul;Seo, Sung;Kim, Jong-Duk;Yoon, Bong-Ki;Lee, Hyo-Won
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.31 no.1
    • /
    • pp.33-38
    • /
    • 2011
  • This experiment was conducted to compare the dry matter yield and forage quality according to the seed mixture of annual legumes and Italian ryegrass (Lolium multiflorum, IRG) on paddy field at the experimental field of Jeollanam-Do Agricultural Research and Extension Services from 2007 to 2008. The five treatments used in this experiment were IRG single (cv. Kowinearly), IRG+Chinese milk vetch mixture, IRG + Crimson clover (cv. Linkarus) mixture, IRG + Austrian winter pea (Pisum sativum subsp. arvense cv. forage Pea) mixture and IRG + Hairy vetch (Vicia villosa. cv. Oregon Common) mixture. And the mixing ratio of Italian ryegrass + annual legumes were 70 : 30 as based mono seed rate. The dry matter (DM) percentage at harvest was 23.6~26.8%. The DM percentage among IRG single and mixture treatments were similar. The yields of fresh and CP were high in IRG + Forage pea mixtures as a 40,100 kg and 625 kg per ha, respectively (p<0.05). The yields of dry matter were high in IRG + Forage pea and IRG + hairy vetch pea mixtures as a 9,470 kg and 9,500 kg per ha, respectively (p<0.05). But the forage quality did not show difference between Italian ryegrass mono-culture and annual legumes mixture. The Av. $P_2O_5$ in IRG+Forage pea mixture was 78 mg/kg and concentration of K were 0.52~0.88. In conclusion, the mixture of IRG and Forage pea, dry matter yield, protein yield increased, and was effective in enhancing the stability of cultivation.