Trace level analysis of Pb in plasma by inductively coupled plasma/mass spectrometry (유도결합플라즈마 질량분석법을 이용한 혈장 중 극미량 납 분석)
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- Analytical Science and Technology
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- v.25 no.3
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- pp.190-196
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- 2012
The human exposure of lead has usually detected the amount of lead in the whole blood, however, this method has a shortcoming to give the information on the short-term exposure to lead. In that sense, it is desirable to estimates the level of lead in plasma to draw the chronic bio-marker of lead exposure even though it is difficult to measure lead of several ng/L. An inductively coupled plasma-mass spectrometry (ICP-MS) method was developed for determining lead in plasma as the chronic bio-marker of lead of workers. To minimize the contamination of lead from the environment, we constructed class 1,000 clean room and compared the amount of floating dust before and after the operation of the clean room. The limit of detection (LOD) and the limit of quantification (LOQ) of lead in fetal bovine serum were 4.3 ng/L and 12.2 ng/L by NIOSH method (statistical calculation method) and 7.0 ng/L and 22.1 ng/L by signal/noise ratio, respectively. The accuracy was in a range of 92.3-101.3%, and the precision of the assay was less than 4% in the samples spiked in the concentration of 20 ng/L and 2,000 ng/L. The method was simple, reproducible and sensitive enough to permit reliable analysis of lead to the ng/L level in plasma and/or serum. The method was also useful for the biological monitoring of chronic exposure to lead.
Environmental DNA (eDNA) is a genetic material derived from organisms in various environments (water, soil, and air). eDNA has many advantages, such as high sensitivity, short investigation time, investigation safety, and accurate species identification. For this reason, it is used in various fields, such as biological monitoring and searching for harmful and endangered organisms. To collect eDNA from a freshwater ecosystem, it is necessary to consider the target organism and gene and a wide variety of items, such as on-site filtration and eDNA preservation methods. In particular, the method of collecting eDNA from the environment is directly related to the eDNA concentration, and when collecting eDNA using an appropriate collection method, accurate (good quality) analysis results can be obtained. In addition, in preserving and extracting eDNA collected from the freshwater ecosystem, when an accurate method is used, the concentration of eDNA distributed in the field can be accurately analyzed. Therefore, for researchers at the initial stage of eDNA research, the eDNA technology poses a difficult barrier to overcome. Thus, basic knowledge of eDNA surveys is necessary. In this study, we introduced sampling of eDNA and transport of sampled eDNA in aquatic ecosystems and extraction methods for eDNA in the laboratory. In addition, we introduced simpler and more efficient eDNA collection tools. On this basis, we hope that the eDNA technique could be more widely used to study aquatic ecosystems and help researchers who are starting to use the eDNA technique.
Background: When particles are absorbed into the human body, they penetrate deep into the lungs and interact with the tissues of the body. Heavy metals in PM2.5 can cause various diseases. The main source of PM2.5 emissions in South Korea's atmosphere has been surveyed to be places of business. Objectives: The concentration of heavy metals in PM2.5 near the Ulsan Industrial Complex was measured and a health risk assessment was performed for residents near the industrial complex for exposure to heavy metals in PM2.5. Methods: Concentrations of heavy metals in PM2.5 were measured at four measurement sites (Ulsan, Mipo, Onsan, Maegok) near the industrial complexes. Heavy metals were analyzed according to the Air Pollution Monitoring Network Installation and Operation Guidelines presented by the National Institute of Environmental Research. Among them, only five substances (Mn, Ni, As, Cd, Cr6+) were targeted. The risk assessment was conducted on inhalation exposure for five age groups, and the excess cancer risk and hazard quotient were calculated. Results: In the risk assessment of exposure to heavy metals in PM2.5, As, Cd, and Cr6+ exceeded the risk tolerance standard of 10-6 for carcinogenic hazards. The highest hazard levels were observed in Onsan and Mipo industrial complexes. In the case of non-carcinogenic hazards, Mn was identified as exceeding the hazard tolerance of 1, and it showed the highest hazard in the Ulsan Industrial Complex. Conclusions: This study presented a detailed health risk from exposure to heavy metals in PM2.5 by industrial complexes located in Ulsan among five age groups. It is expected to be utilized as the basis for preparing damage control and industrial emission reduction measures against PM2.5 exposure at the Ulsan Industrial Complex.
In this study, formation background of biodiversity and its changes in the process of geologic history, and effects of climate change on biodiversity and human were discussed and the alternatives to reduce the effects of climate change were suggested. Biodiversity is 'the variety of life' and refers collectively to variation at all levels of biological organization. That is, biodiversity encompasses the genes, species and ecosystems and their interactions. It provides the basis for ecosystems and the services on which all people fundamentally depend. Nevertheless, today, biodiversity is increasingly threatened, usually as the result of human activity. Diverse organisms on earth, which are estimated as 10 to 30 million species, are the result of adaptation and evolution to various environments through long history of four billion years since the birth of life. Countlessly many organisms composing biodiversity have specific characteristics, respectively and are interrelated with each other through diverse relationship. Environment of the earth, on which we live, has also created for long years through extensive relationship and interaction of those organisms. We mankind also live through interrelationship with the other organisms as an organism. The man cannot lives without the other organisms around him. Even though so, human beings accelerate mean extinction rate about 1,000 times compared with that of the past for recent several years. We have to conserve biodiversity for plentiful life of our future generation and are responsible for sustainable use of biodiversity. Korea has achieved faster economic growth than any other countries in the world. On the other hand, Korea had hold originally rich biodiversity as it is not only a peninsula country stretched lengthily from north to south but also three sides are surrounded by sea. But they disappeared increasingly in the process of fast economic growth. Korean people have created specific Korean culture by coexistence with nature through a long history of agriculture, forestry, and fishery. But in recent years, the relationship between Korean and nature became far in the processes of introduction of western culture and development of science and technology and specific natural feature born from harmonious combination between nature and culture disappears more and more. Population of Korea is expected to be reduced as contrasted with world population growing continuously. At this time, we need to restore biodiversity damaged in the processes of rapid population growth and economic development in concert with recovery of natural ecosystem due to population decrease. There were grand extinction events of five times since the birth of life on the earth. Modern extinction is very rapid and human activity is major causal factor. In these respects, it is distinguished from the past one. Climate change is real. Biodiversity is very vulnerable to climate change. If organisms did not find a survival method such as 'adaptation through evolution', 'movement to the other place where they can exist', and so on in the changed environment, they would extinct. In this respect, if climate change is continued, biodiversity should be damaged greatly. Furthermore, climate change would also influence on human life and socio-economic environment through change of biodiversity. Therefore, we need to grasp the effects that climate change influences on biodiversity more actively and further to prepare the alternatives to reduce the damage. Change of phenology, change of distribution range including vegetation shift, disharmony of interaction among organisms, reduction of reproduction and growth rates due to odd food chain, degradation of coral reef, and so on are emerged as the effects of climate change on biodiversity. Expansion of infectious disease, reduction of food production, change of cultivation range of crops, change of fishing ground and time, and so on appear as the effects on human. To solve climate change problem, first of all, we need to mitigate climate change by reducing discharge of warming gases. But even though we now stop discharge of warming gases, climate change is expected to be continued for the time being. In this respect, preparing adaptive strategy of climate change can be more realistic. Continuous monitoring to observe the effects of climate change on biodiversity and establishment of monitoring system have to be preceded over all others. Insurance of diverse ecological spaces where biodiversity can establish, assisted migration, and establishment of horizontal network from south to north and vertical one from lowland to upland ecological networks could be recommended as the alternatives to aid adaptation of biodiversity to the changing climate.
Domestic cats (Felis catus) introduced to insular environments can be invasive predators that often threaten endemic species and cause biodiversity loss or local extinction on the island. This study was conducted from March to July 2018 to understand the population size, home range, and spatial use of cats introduced to Mara Islet (N 33° 07', E 126° 16') in Jeju Special Governing Province, the Republic of Korea. Observation records based on their natural marks revealed that there were 20 adult cats on Mara Islet. A capture-recapture method also estimated 20 adult individuals (95% confidence interval: 20-24 individuals). According to our telemetry study on ten adults deployed with GPS-based telemetry units, the home range size was 12.05±6.99 ha (95% KDE: kernel density estimation), and the core habitat size was 1.60±0.77 ha (50% KDE). There were no significant differences in the home range and core habitat sizes by sex. The home range of domestic cats overlapped with the human residential area, where they might secure easy foods. Five of ten tracked cats were active at potential breeding colonies for the Crested Murrlet (Synthliboramphus wumizusume), and six approached potential breeding areas of the Styan's Grasshopper Warbler (Locustella pleskei), suggesting the predation risk of the two endangered species by cats. This study provides novel information on the population size and home range of introduced cats on Mara Islet which is an important stopover site of migratory birds as well as a breeding habitat of the two endangered avian species. Reducing the potential negative impacts of the introduced cats on migratory birds and the endangered species on Mara Islet requires monitoring of the predation rate of birds by cats, the population trends of cats and endangered breeding birds as well as the effective cat population control and management.
Clinically, it is almost impossible for a physician to distinguish subtle changes of frequency spectrum by using a stethoscope alone especially in the early stage of thrombus formation. Considering that reliability of mechanical valve is paramount because the failure might end up with patient death, early detection of valve thrombus using noninvasive technique is important. Thus the study was designed to provide a tool for early noninvasive detection of valve thrombus by observing shift of frequency spectrum of acoustic signals with computer aid diagnosis system. A thrombus model was constructed on commercialized mechanical valves using polyurethane or silicon. Polyurethane coating was made on the valve surface, and silicon coating on the sewing ring of the valve. To simulate pannus formation, which is fibrous tissue overgrowth obstructing the valve orifice, the degree of silicone coating on the sewing ring varied from 20%, 40%, 60% of orifice obstruction. In experiment system, acoustic signals from the valve were measured using microphone and amplifier. The microphone was attached to a coupler to remove environmental noise. Acoustic signals were sampled by an AID converter, frequency spectrum was obtained by the algorithm of spectral analysis. To quantitatively distinguish the frequency peak of the normal valve from that of the thrombosed valves, analysis using a neural network was employed. A return map was applied to evaluate continuous monitoring of valve motion cycle. The in-vivo data also obtained from animals with mechanical valves in circulatory devices as well as patients with mechanical valve replacement for 1 year or longer before. Each spectrum wave showed a primary and secondary peak. The secondary peak showed changes according to the thrombus model. In the mock as well as the animal study, both spectral analysis and 3-layer neural network could differentiate the normal valves from thrombosed valves. In the human study, one of 10 patients showed shift of frequency spectrum, however the presence of valve thrombus was yet to be determined. Conclusively, acoustic signal measurement can be of suggestive as a noninvasive diagnostic tool in early detection of mechanical valve thrombosis.
The ocean is a significant sink for atmospheric anthropogenic CO2, absorbing one-third of the total CO2 emitted by human activities. In return, oceans have experienced significant declines in seawater pH and the aragonite saturation state also called ocean acidification. This study evaluates the distribution of aragonite saturation state, an indicator to assess the potential threat from ocean acidification, by combining newly obtained data from the west coast of South Korea with previous datasets covering the Yellow Sea, East Sea, northern South China Sea, and southeast coast of South Korea. In general, offshore waters absorb atmospheric CO2; however, most of the collected water samples show aragonite oversaturation. On the southeast coast, the aragonite saturation state was significantly affected by river discharge and associated variables, such as freshwater input with nutrients, seasonal stratification, biological carbon fixation, and bacterial remineralization. In summer, hypoxia and mixing with relatively acidic freshwater made the Jinhae and Gwangyang Bays undersaturated with respect to aragonite, possibly threatening marine organisms with CaCO3 shells. However, widespread aragonite undersaturation was not observed on the west coast, which receives considerable river water discharge. In addition, occasional upwelling events may have worsened the ocean acidification in the southwestern part of the East Sea. These results highlight the importance of investigating site-specific ocean acidification processes in coastal waters. Along with the above-mentioned seasonal factors, the dissolution of atmospheric CO2 and the deposition of atmospheric acidic substances will continue to reduce the aragonite saturation state in Korean waters. To protect marine ecosystems and resources, an ocean acidification monitoring program should be established for Korean waters.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70