• Title/Summary/Keyword: filtration coefficient

Search Result 93, Processing Time 0.028 seconds

Comparison for Glomerular Filtration Rate in Gamma Camera Systems Using Dynamic Renal Phantom System (동적신장팬텀시스템 개발에 따른 장비별 사구체여과율의 비교)

  • Kang, Chun Goo;Park, Hoon-Hee;Oh, Shin Hyun;Lee, Han Wool;Kim, Jung Yul;Oh, Joo Yung;Lee, Ju Young;Kim, Jae Sam;Lee, Chang Ho
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.17 no.2
    • /
    • pp.3-9
    • /
    • 2013
  • Purpose: Currently commercially available phantom can reproduce and evaluate only a static situation, the study is incomplete research on phantom and system which is can confirmed functional situation in the kidney by time through dynamic phantom and blood flow velocity, various difference according to the amount of radioactive. Therefore, through this study, it has produced the dynamic kidney phantom to reproduce images through the dynamic flow of the kidney, it desire to evaluate the usefulness of nuclear medicine imaging. Materials and Methods: The production of the kidney phantom was fabricated based on the normal adult kidney, in order to reproduce the dynamic situation based on the fabricated kidney phantom, in this study it was applied the volume pump that can adjust the speed of blood flow, so it can be integrated continuously radioactive isotopes in the kidney by using $^{99m}Tc-pertechnate$. Used the radioactive isotope was supplied through the two pump. It was confirmed the changes according to the infusion rate, radioactive isotopes and the different injection speeds on the left and right, analysis of the acquired images was done by drawn ten times ROI in order to check the reproducibility of each on the front and rear of the kidney and bladder. Results: Under the same conditions infusion rate 40 mL/min fixed to adjust the pressure of the pump when the radiopharmaceuticals between 2-3 minutes in the most integrated in the kidney phantom was excreted inthe bladder. Glomerular filtration rate (GFR), respectively, by each device SYMBIA 1,091 mL/min, FORTE 1,232 mL/min, ARGUS 1,264 mL/min, INFINIA 1,302 mL/min in that there isno statistically significant difference was found, Tmax values and T1/2 values stars from all equipment with no statistically significant difference was found. CV values of the coefficient of variation less than 5% was found to be repeatable, and to 2.67% of the lowest SYMBIA appeared, INFINIA was the highest in the 4.86%. Conclusion: Through this study, the results showed that the dynamic kidney phantom system is able to similarly reproduce renogram in the actual clinical. Especially, the depicted over time for the flow to be excreted through the kidney into the bladder was adequately reproduce, it is expected to be utilized as basic data to check the quality of the dynamic images. In addition, it is considered to help in the field of functional imaging and quality control.

  • PDF

Study on Knowledge Levels of Pre-dialysis, Chronic Renal Failure Patients at Glomerular Filtration Rates (GFRs) and Their Educational Demands (사구체 여과율에 따른 투석 전 만성 신부전 환자의 질병 관련 지식 정도와 교육 요구도 조사)

  • Kim, Hye-Won;ChoiKwon, S-Mi
    • Journal of Korean Biological Nursing Science
    • /
    • v.12 no.2
    • /
    • pp.114-126
    • /
    • 2010
  • Purpose: To examine the levels of the disease-related knowledge and educational demands of pre-dialysis, chronic renal failure patients at different GFRs and stages. Methods: This study used a cross-sectional survey and aimed at 116 pre-dialysis, chronic renal failure patients, who were registered and received regular treatment from December 1 to December 31, 2009 at the nephrology departments of tertiary medical centers in Seoul. Stages were classified into Stage 3, 4 and 5 depending on GFR ranges. To measure the levels of knowledge and educational demands, the tool, which were first invented by Young Ae Lim (1996) and then modified by Hyo Sun Lim (2005) to adjust the knowledge and educational demands measuring tool for hemodialysis patients to pre-dialysis patients with chronic renal failure, was used. Collected data was analyzed with the SPSS WIN 12.0 program (average, standard deviation, Pearson's correlation coefficient, t-test and ANOVA). Results: There was a significant difference in the disease-related knowledge levels of the subjects at each stage (F=24.41, p=.000). The Scheffe post hoc test confirmed that patients at higher stages had higher levels of knowledge of their disease. Also, although the results showed that patients at higher stages had higher educational demands, there was no significant difference among the groups (F=1.259, p=.288). Conclusion: As patients have different levels of knowledge of the disease and educational demands depending on their stages, it is important to develop and use a systematic education program that reflects the demands and levels of patients at each stage in order to help pre-dialysis patients with chronic renal failure with self-management and improve their quality of life.

Study on Hindered Diffusion of Single Polyelectrolyte Chain in Micro-Pores by Employing Brownian Dynamics Simulations (브라운 동력학 시뮬레이션에 의한 미세기공에서 단일한 다가전해질 사슬의 제한확산 연구)

  • 전명석;곽현욱
    • Membrane Journal
    • /
    • v.12 no.4
    • /
    • pp.207-215
    • /
    • 2002
  • The hindered diffusion in confined spaces is an important phenomenon to understand in a micro-scale the filtration mechanism determined by the particle motion in membrane pores. Compared to the case of spherical colloids, both the theoretical investigations and the experiments on the hindered diffusion of polyelectrolytes is actually more difficult, due to lots of relevant parameters resulting from the complicated conformational properties of the polyelectrolyte chain. We have successfully performed the Brownian dynamics simulations upon a single polyeiectrolyte confined in a slit-like pore, where a coarse-grained bead-spring model incorporated with Debye-Huckel interaction is properly adopted. For the given sizes of both the polyelectrolyte and the pore width, the hindered diffusion coefficient decreases as the solution ionic concentration decreases. It is evident that a charge effect of the pore wall enhances the hindered diffusion of polyelectrolyte. Simulation results allow us to make sense of the diffusive transport through the micro-pore, which is restricted by the influences of the steric hindrance of polyelectrolytes as well as the electrostatic repulsion between the polyelectrolytes and pore wall.

Phosphate Removal from Aqueous Solution by Aluminum (Hydr)oxide-coated Sand

  • Han, Yong-Un;Park, Seong-Jik;Park, Jeong-Ann;Choi, Nag-Choul;Kim, Song-Bae
    • Environmental Engineering Research
    • /
    • v.14 no.3
    • /
    • pp.164-169
    • /
    • 2009
  • A powder form of aluminum (hydr)oxides is not suitable in wastewater treatment/filtration systems because of low hydraulic conductivity and large sludge production. In this study, aluminum (hydr)oxide-coated sand (AOCS) was used to remove phosphate from aqueous solution. The properties of AOCS were analyzed using a scanning electron microscopy (SEM) combined with an energy dispersive X-ray spectrometer (EDS) and an X-ray diffractometer (XRD). Kinetic batch, equilibrium batch, and closed-loop column experiments were performed to examine the adsorption of phosphate to AOCS. The XRD pattern indicated that the powder form of aluminum (hydr)oxides coated on AOCS was similar to a low crystalline boehmite. Kinetic batch experiments demonstrated that P adsorption to AOCS reached equilibrium after 24 h of reaction time. The kinetic sorption data were described well by the pseudo second-order kinetic sorption model, which determined the amount of P adsorbed at equilibrium ($q_e$ = 0.118 mg/g) and the pseudo second-order velocity constant (k = 0.0036 g/mg/h) at initial P concentration of 25 mg/L. The equilibrium batch data were fitted well to the Freundlich isotherm model, which quantified the distribution coefficient ($K_F$ = 0.083 L/g), and the Freundlich constant (1/n = 0.339). The closed-loop column experiments showed that the phosphate removal percent decreased from 89.1 to 41.9% with increasing initial pH from 4.82 to 9.53. The adsorption capacity determined from the closed-loop experiment was 0.239 mg/g at initial pH 7.0, which is about two times greater than that ($q_e$ = 0.118 mg/g) from the kinetic batch experiment at the same condition.

Experimental studies of validation and stability of Sweet Bee Venom using HPLC (Sweet BV의 조제물 농도분석 및 안정성 확인을 위한 시험적 연구)

  • Kang, Kye-Sung;Kwon, Ki-Rok
    • Journal of Pharmacopuncture
    • /
    • v.12 no.4
    • /
    • pp.33-50
    • /
    • 2009
  • Objectives : This study was conducted to confirm validation and stability of concentration analysis method of pure melittin (Sweet Bee Venom-Sweet BV) extracted from the bee venom by utilizing protein isolation method of gel filtration. Methods : All experiments were conducted at Biotoxtech, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Standard solutions of melittin (SIGMA, USA) and test substances were dispensed and were analyzed with HPLC for Sweet BV to secure the validation of analysis. Results : 1. Measurement of system suitability of Sweet BV satisfied criterion of below 3%. 2. Confirming Linearity of Sweet BV in 10-200${\mu}g/m\ell$ solution yielded correlation coefficient (r) of 0.995 and accuracy of 85-115% which satisfy criterion. 3. Measurement of Specificity of Sweet BV didn't yield any substance affecting the peak of test substances, but detected at 21.22min verified as the test substance. 4. Confirming Intra-day of Sweet BV, accuracy and precision of 0.1, 100${\mu}g/m\ell$ were 105.70, 95.81 and 0.66, 0.73, respectively, satisfying both criteria of accuracy (85-115%) and precision (within 10%). 5. To measure Stability in autosampler, all samples used in Intra-day reproducibility sat in the autosampler for five hours and were re-analyzed. Both variability and precision satisfied the criteria. 6. Homogeneity of Sweet BV (0.1, 100${\mu}g/m\ell$) at upper, middle, and lower layers all satisfied the accuracy and precision criteria. 7. Stability of Sweet BV (0.1, 100${\mu}g/m\ell$) at room temperature for four hours and refrigerated for 7 days all satisfied the criterion. 8. For the measurement of Quality control, QC samples measured on the first and eighth day all satisfied accuracy and precision criteria. Conclusion : Above experiment data satisfies validation and stability of concentration analysis method of Sweet BV.

Ammonia Removal Characteristics in Membrane Contactor System Using Tubular PTFE Membrane (관형 PTFE 분리막을 이용한 막 접촉기(Membrane Contactor) 시스템에서 암모니아의 제거 특성)

  • Ahn, Yong-Tae;Hwang, Yu-Hoon;Shin, Hang-Sik
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.33 no.5
    • /
    • pp.353-358
    • /
    • 2011
  • In this study, ammonia removal characteristics in membrane contactor system under various operating conditions were evaluated. The mass transfer coefficient was used to quantitatively compare the effect of various operation conditions on ammonia removal efficiency. Effective removal of ammonia was possible with the tubular PTFE membrane contactor system at all tested conditions. Among the various operation parameters, contact time and solution pH showed significant effect on ammonia removal mechanism. Overall ammonia removal rate was not significantly affected by influent suspended solution concentration unlike other pressure driven membrane filtration processes. Also the osmotic distillation phenomena which deteriorate the mass transfer efficiency can be minimized by preheating of strip solution. Membrane contactor system can be a possible alternative to treat high strength nitrogen wastewater by optimizing operation conditions such as stripping solution flow rate, influent wastewater temperature, and influent pH.

Development of an Oil Mist Collector Equipped with Centrifugal De-oiling System (원심력 필터 재생기능을 갖춘 오일 미스트 여과 집진장치 개발)

  • Kim, Tae-Hyeung;Seo, Jeoung-Yoon;Ha, Hyun-Chul;Kim, Jong-Cheul;Cho, Jin-Ho
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.15 no.3
    • /
    • pp.166-175
    • /
    • 2005
  • Health effects associated with metal working fluid (MWF) exposures include dermatitis, respiratory disease, hypersensitive pneumonitis, and asthma. Frequently, occupational exposures to MWFs are controlled by ventilating an enclosure with an air cleaning unit that includes a fan preceded by various kinds of filtration. There are several kinds of air cleaning units used in machining centers. But the associated troubles have hindered from efficiently using these devices. The main problem is the relatively short period of filter replacement. The reason is that the air cleaning units usually do not have the de-oiling systems, thus leading the earlier clogging of filters and reducing the flow rate of hood. Thus, the first stage of study was conducted to overcome this problem by developing the new oil mist collector equipped with the easy de-oiling system. The principle of de-oiling is that the centrifugal force generated by spinning the drum covered by filter fabric separates oils from the filter fabric. It would be very similar to the spin-dry laundry. By adopting this de-oiling technique, the problems associated with the conventional oil mist collectors could be solved. Several tests/analyses were performed to make the lab-scale oil mist collector. The collection efficiencies and the de-oiling efficiencies of commercially available filter fabrics were tested. Subsequently, the endurance test were conducted by observing SEM photos of filter fabrics and measuring tensile strength/expansion coefficient after spinning the filter drum for 20 minutes at the different rotation speeds. By doing these experiments, the most appropriate filter fabric and rotation speed/duration were selected. Finally, the new oil mist collector was designed. In the near future, this device must be tested in the real machining center.

Isolation, Purification, and Partial Characterization of an AMP Deaminase from Saccharomyces cerevisiae D

  • Kim, Myung-Hee;Lee, Jung-Kee;Kim, Hyung-Kwoun;Oh, Tae-Kwang
    • Journal of Microbiology and Biotechnology
    • /
    • v.9 no.4
    • /
    • pp.429-435
    • /
    • 1999
  • An adenosine 5'-monophosphate deaminase (AMP aminohydrolase, EC 3.5.4.6) was purified to homogeneity from the cell-free extract of Saccharomyces cerevisiae DKCTC7248. The molecular mass of subunit was estimated to be 80 kDa on SDS-PAGE, and that of the holoenzyme was shown to be 240 kDa by gel filtration. The isoelectric point of the enzyme (AMP deaminase D) was determined to be 6.2. The AMP deaminase D was specific towards AMP with an apparent $K_m$ value of 4.1 mM and a Hill coefficient, $n_H$, of 2.2. Both ATP and ADP were positive allosteric effectors of the AMP deaminase D: The apparent $K_{m}$ was decreased to 1.6 mM and 3.3 mM in the presence of 0.1 mM ATP and ADP, respectively, lowering $n_{H}$ to 1.0. Univalent cations like $K^+, Na^+ and Li^ +$ activated the enzyme but some divalent cations such as $Cu^{ 2+} and Cd^{2+}$ showed strong inhibitory effects. This enzyme displayed optimum activity at $30^{\circ}C$ and pH 7.0. In addition, it was stable up to $45^{\circ}C$ and over a wide pH range(pH 5.5-9.0). Amino acid sequences of its N-terminal region were analyzed to be ADYKMQMFADDA.

  • PDF

Reflection on Kinetic Models to the Chlorine Disinfection for Drinking Water Production

  • Lee, Yoon-Jin;Nam, Sang-ho
    • Journal of Microbiology
    • /
    • v.40 no.2
    • /
    • pp.119-124
    • /
    • 2002
  • Experiments for the characterization of inactivation were performed in a series of batch processes with the total coliform used as a general indicator organism based on the chlorine residuals as a disinfectant. The water samples were taken from the outlet of a settling basin in a conventional surface water treat- ment system that is provided with the raw water drawn from the mid-stream of the Han River, The inactivation of total coliform was experimentally analysed for the dose of disinfectants contact time, filtration and mixing intensity. The curves obtained from a series of batch processes were shaped with a general tailing-off and biphasic mode of inactivation, i.e. a sharp loss of bacterial viability within 15 min followed by an extended phase. In order to observe the effect of carry-over suspended solids on chlorine consumption and disinfection efficiency, the water samples were filtered, prior to inoculation with coliforms, with membranes of both 2.5$\mu$m and 11.0 $\mu$m pore size, and with a sand tilter of 1.0 mm in effective size and of 1.4 in uniformity coefficient. As far as the disinfection efficiency is concerned, there were no significant differences. The parameters estimated by the models of Chick-Wat-son, Hom and Selleck from our experimental data obtained within 120 min are: log(N/N$\_$0/)=-0.16CT with n=1, leg(N/N$\_$0/)=-0.71C$\^$0.87/ with n 1 for the Chick-Watson model, log (N/N$\_$0/)=-1.87C$\^$0.47/ T$\^$0.36/ for the Hom model, log (MHo)=-2.13log (1+CT/0.11) for the Selleck model. It is notable that among the models reviewed with regard to the experimental data obtained, the Selleck model appeared to most closely resemble the total coliform survival curve.

Purification and Properties of the Factor from Arthrobacter luteus, Capable of Accelerating the Lysis of Yeast Cell Walls (Arthrobacter luteus가 생산(生産)하는 효모(酵母) 세포벽(細胞壁) 용해(溶解) 촉진인자(促進因子)의 정제(精製) 및 그 이화학적(理化學的) 성질(性質))

  • Oh, Hong Rock;Aizono, Yasuo;Shimoda, Tadahisa;Masaru, Funatsu
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.12 no.4
    • /
    • pp.387-394
    • /
    • 1983
  • The factor, which was capable of accelerating the yeast cell wall lysis of the zymolyase(${\beta}-1$, 3-glucanase), was purified to a homogeneous state from the protease fraction of the crude zymolyase by Sephadex G-75 gel filtration and preparative polyacrylamide gel disc electrophoresis. The molecular weight of the purified factor was estimated to be 40,500 by SDS-polylacrylamide gel disc electrophoresis and it's iso-electric point was pH 9.6. The factor was found to be a basic protease consisted of single polypeptide chain with 395 amino acid residues and it showed the $E_{280,cm}^{1%}$ of 11.9 and the molecular extinction coefficient of $4.83{\times}10^4$, respectively.

  • PDF