• Title/Summary/Keyword: concentration measure

Search Result 1,484, Processing Time 0.03 seconds

Maximum TE Setting Range for Quantitatively Evaluating T2 Relaxation Time : Phantom Study (T2 이완시간의 정량적 평가에 있어서 Maximum TE의 설정 범위에 대한 연구 : 팬텀연구)

  • Park, Jin Seo;Kim, Seong-Ho
    • Journal of radiological science and technology
    • /
    • v.41 no.1
    • /
    • pp.25-31
    • /
    • 2018
  • This study aimed to evaluate the range of maximum TE that could measure T2 relaxation time accurately by setting diverse maximum TE with using contrast medium phantoms. Contrast medium phantoms ranging from low to high concentrations were made by using Gadoteridol. The relaxation time and relaxation rate were compared and evaluated by conducting T2 mapping by using reference data based on various TEs and data obtained from different maximum TEs. It was found that accurate T2 relaxation time could be expressed only when the maximum TE over a certain range was used in the section with long T2 relaxation time, such as the low concentration section of saline or gadolinium contrast medium. Therefore, the maximum TE shall be longer than the T2 relation time for accurately maturing the T2 relaxation of a certain tissue or a substance.

Review of the Extraction Methods of Soil Extracts, Soil Elutriates, and Soil Suspensions for Ecotoxicity Assessments (생태독성평가를 위한 Soil Extracts, Soil Elutriates, Soil Suspensions 추출기법)

  • Nam, Sun-Hwa;An, Youn-Joo
    • Journal of Soil and Groundwater Environment
    • /
    • v.19 no.3
    • /
    • pp.15-24
    • /
    • 2014
  • Soil pollution has been recognized as a serious problem because it causes groundwater pollution through medium contacts. Although concentration of individual chemical could be more easily measured by physico-chemical analysis, it is not easy to consider the bioavailability of edaphic receptors living in soil or groundwater. To measure the toxicity of soil, the soil extracts (soil elutriates or soil suspensions in the other words) are often used due to the difficulties of extracting soil pore water. In this study, we reviewed 15 toxicity test methods found in literature to analyze the detail of each extraction method and to recommend the most frequently used extraction methods. The identified most commonly used extraction methods are as following: The 1 : 4 soil:water ratio, 24 hours shaking time, room temperature, dark, and separation of supernatant using a $0.45{\mu}m$ pore size filter.

Yeast Loading BOD Biosensor (효모균을 이용한 BOD Biosensor)

  • Kim, Mal-Nam
    • The Korean Journal of Mycology
    • /
    • v.23 no.4 s.75
    • /
    • pp.354-358
    • /
    • 1995
  • A yeast loading biochemical oxygen demand (BOD) sensor was designed and constructed to quickly measure the concentration of biologically assimilable organic substances dissolved in water as BOD values to feed back to the waste water treating processes. The sensitivity of the BOD sensor reached maximum at around pH 7.0 and $30^{\circ}C$ where yeast showed the highest assimilation activity. Biomass also affected the sensor output, and biomass of $ 0.14\;mg/cm^2$ on the dialysis membrane appeared to be the optimum cell mass level. The sensitivity of the sensor depended on the kinds of pollutants and increased considerably when the yeast was preincubated in the solution of respective pollutants before loading on the sensor.

  • PDF

Surface-Active Properties of Sodium bis-Alkyl Sulfonatosuccinate (술폰화된 호박산 알킬에스테르류의 계면성)

  • Kim, Myeong-Soo;Jeong, Hwan-Kyeong;Yoon, In-Young;Nam, Ki-Dae
    • Journal of the Korean Applied Science and Technology
    • /
    • v.18 no.2
    • /
    • pp.95-102
    • /
    • 2001
  • Recently, there has been considerably interested in the development to new functional gemini type anionic surfactant, sodium bis-n-alkyl sulfonatosuccinate, had been synthesized through the addition reaction of sodium bisulfite to bis-n-alkyl maleate, in which water was azeotropically distilled by adding benzene to the reaction system, gave a good yield. All the surface activities including krafft point, surface tension, emulsion power and foaming were measure and cmc was evaluated in dilute solution. This results showed a lower ability in $27{\sim}30dyne/cm$ than single-chain surfactant with $32{\sim}35dyne/cm$ to surface tension. Also its cmc value much smaller in $(6.5{\sim}10){\times}10^{-4}mca{\ell}/{\ell}$ than single-chain surfactant with $(40{\sim}45){\times}10^{-4}mca{\ell}/{\ell}$ concentration. In foaming ability and foam stability of gemini surfactant had especially a good ability in approximately $100{\sim}150ml$, and in emulsing power they exhibited a good emulsing phase and stability, and Krafft points were $0{\sim}10^{\circ}C$.

Determination of Total Phenolic Compounds from the Fruit of Rubus coreanum and Antioxidative Activity (복분자 열매의 총 페놀성분의 정량 및 항산화 활성)

  • 이종원;도재호
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.29 no.5
    • /
    • pp.943-947
    • /
    • 2000
  • The purpose of this study was to investigate the extraction method of phenolic compounds from Rubus coreanum and antioxidative activity. antioxidative activities of Rubus coreanum were tested with ability of donating hydrogen to DPPH, and HPLC, fluorometry which measure the amount of MDA after reacting linoleic acid with $H_2O$$_2$, and LDL with $H_2O$$_2$ and FeCl$_2$. The most suitable extraction conditions of the phenolic compounds from Rubus coreanum was 3 times with 60% ethanol, and the yield of extract containing 35% moisture was 15.28%. In extraction efficacy of phenolic compounds, 60% ethanol was superior to water as extraction solvent, and extraction efficacy with 60% ethanol did not differ from disolving by water after evaporation of 60% ethanol extract. 60% ethanol extract of Rubus coreanum had an ability of hydrogen donating to DPPH, MDA determination showed the antioxidative effect with inhibition ratio of 77.91% on linoleic acid oxidation by addition of Rubus coreanum extract with the concentration of 1.500 ppm. and about 65.74% of LDL oxidation was inhibited by addition of 1,000 ppm.

  • PDF

Drug Targeting to Lungs by Way of Microspheres

  • Harsha, N. Sree;Rani, R.H. Shobha
    • Archives of Pharmacal Research
    • /
    • v.29 no.7
    • /
    • pp.598-604
    • /
    • 2006
  • In many conventional drug delivery systems in vogue, failure to deliver efficient drug delivery at the target site/organs; is evident as a result, less efficacious pharmacological response is elicited. Microspheres can be derived a remedial measure which can improve site-specific drug delivery to a considerable extent. As an application, Lung-targeting Ofloxacin-loaded gelatin microspheres (GLOME) were prepared by water in oil emulsion method. The Central Composite Design (CCD) was used to optimize the process of preparation, the appearance and size distribution were examined by scanning electron microscopy, the aspects such as in vitro release characteristics, stability, drug loading, loading efficiency, pharmacokinetics and tissue distribution in albino mice were studied. The experimental results showed that the microspheres in the range of $0.32-22\;{\mu}m$. The drug loading and loading efficiency were 61.05 and 91.55% respectively. The in vitro release profile of the microspheres matched the korsmeyer’s peppas release pattern, and release at 1h was 42%, while for the original drug, ofloxacin under the same conditions 90.02% released in the first half an hour. After i.v. administration (15 min), the drug concentration of microspheres group in lung in albino mice was $1048\;{\mu}g/g$, while that of controlled group was $6.77\;{\mu}g/g$. GLOME found to release the drug to a maximum extent in the target tissue, lungs.

Recent advances in the feeding and nutrition of dairy goats

  • Goetsch, Arthur Louis
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.32 no.8_spc
    • /
    • pp.1296-1305
    • /
    • 2019
  • There have been recent advances concerning research of the feeding and nutrition of dairy goats in a wide array of areas. Ruminally emitted methane and supplementary feedstuffs to a lesser extent make appreciable contributions to the carbon footprint of dairy goats, with the former affected by type of production system and associated dietary characteristics. Unique behavior of goats necessitates careful consideration of the nature of confinement facilities to achieve optimal production by animals differing in social hierarchy. Physiological conditions such as nutritional needs and perhaps health status may influence diet selection by goats in both grazing and confinement settings. Some research suggests that low concentrations of protein and fat in milk of high-yielding dairy goat breeds could involve the type and nature of dietary ingredients as influencing end products of ruminal fermentation. With the relationship between milk urea nitrogen concentration and efficiency of dietary protein utilization, through future research the measure may be a useful tool for diet formulation as in dairy cattle. Effects of dietary inclusion of sources of fats and oils vary considerably depending on their nature, as is also true for byproduct feedstuffs and conventional ones being substituted for. Supplementation of dairy goats with sources of polyunsaturated fatty acids can affect oxidative stress and various feedstuffs influence antioxidant status; however, research addressing the significance of such changes under practical production settings would be beneficial.

Exercise induced Right Ventricular Fibrosis is Associated with Myocardial Damage and Inflammation

  • Rao, Zhijian;Wang, Shiqiang;Bunner, Wyatt Paul;Chang, Yun;Shi, Rengfei
    • Korean Circulation Journal
    • /
    • v.48 no.11
    • /
    • pp.1014-1024
    • /
    • 2018
  • Background and Objectives: Intense exercise (IE) induced myocardial fibrosis (MF) showed contradictory findings in human studies, making the relationship between IE and the development of MF unclear. This study aims to demonstrate exercise induced MF is associated with cardiac damage, and inflammation is essential to the development of exercise induced MF. Methods: Sprague-Dawley rats were submitted to daily 60-minutes treadmill exercise sessions at vigorous or moderate intensity, with 8-, 12-, and 16-week durations; time-matched sedentary rats served as controls. Enzyme-linked immunosorbent assay (ELISA) was used to measure serum cardiac troponin I (cTnI) concentration. After completion of the exercise protocol rats were euthanized. Biventricular morphology, ultrastructure, and collagen deposition were then examined. Protein expression of interleukin $(IL)-1{\beta}$ and monocyte chemotactic protein (MCP)-1 was evaluated in both ventricles. Results: After IE, right but not left ventricle (LV) MF occurred. Serum cTnI levels increased and right ventricular damage was observed at the ultrastructure level in rats that were subjected to long-term IE. Leukocyte infiltration into the right ventricle (RV) rather than LV was observed after long-term IE. Long-term IE also increased protein expression of proinflammation factors including $IL-1{\beta}$ and MCP-1 in the RV. Conclusions: Right ventricular damage induced by long-term IE is pathological and the following inflammatory response is essential to the development of exercise induced MF.

NMR-based monitoring of the hangover curing effects of deep sea water minerals

  • Ha, Jong-Myung;Woo, Young Min;Kim, Andre
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.22 no.4
    • /
    • pp.82-90
    • /
    • 2018
  • The term "hangover" refers to symptoms such as headache, heartburn, nausea, and dizziness caused by acetaldehyde created through alcohol decomposition in the body after alcohol intake. Many scientists have conducted research on diverse drugs, foods, and medicinal herbs aimed at eliminating hangovers. However, research on metabolism to objectively verify or measure their effects on hangover symptoms has been lacking. Accordingly, in this study, deep sea water minerals were administered orally at varying concentrations to rats that consumed alcohol, and changes in the levels of amino acids in their bodies were measured using nuclear magnetic resonance spectroscopy to gauge the minerals' effects on hangover symptoms. Thus far, biochemical research on hangover cures has been confined to basic research measuring changes in the levels of alcohol dehydrogenase and acetaldehyde dehydrogenase as well as in the concentrations of ethanol, acetaldehyde, and acetate using spectroscopes such as enzyme-linked immunosorbent assay kits or gas chromatography-mass spectrometers. In comparison, this study presents pharmacokinetic research that simultaneously tracked biomaterials including amino acids and organic acids, metabolites associated with hangover, to clarify hangover mechanisms more specifically. In addition, this study examined hangover mechanisms without an external supply of tracked materials not overlapping with alcohol metabolism-related materials, such as external amino acids and sugars.

Non-Invasive HbA1c Measurement Using Two-Wavelength Raman Scattering (2 파장 라만 산란을 이용한 비침습적 HbA1c 측정)

  • Yang, Jooran;Kim, Hyungpyo
    • Journal of Sensor Science and Technology
    • /
    • v.28 no.5
    • /
    • pp.305-310
    • /
    • 2019
  • The purpose of this study is to classify the concentration of HbA1c (glycosylated hemoglobin), which is an indicator in the management of accurate blood glucose level in diabetic patients, using a non-invasive optical property measurement method. To measure the optical properties of HbA1c, the optical source uses LEDs and laser diodes of 400 nm in the visible region and 1450 nm in the nearinfrared region using thermopile to detect the Raman scattering intensity. An HbA1c control solution was used. As a result, the optical properties of 5% (normal) and 9% (abnormal) HbA1c control solutions showed specificity in which the output values were reversed at 850 nm and 950 nm, respectively. This property was applied to distinguish between normal and abnormal values in diabetes. In addition, considering tissue penetration depths for non-invasive measurements, two wavelengths were determined to be effective in distinguishing the concentrations of HbA1c control solutions at 5%, 7%, and 9%.