1.A study on the color difference between Au-Pt alloy porcelain and Ni-Cr alloy porcelain.
Yong LI ; Yunfeng ZHAO ; Hong LI
West China Journal of Stomatology 2003;21(3):217-219
OBJECTIVETo investigate the color difference between Au-Pt alloy porcelain and Ni-Cr alloy porcelain.
METHODS30 metal-ceramic specimens with different dentin porcelain thickness were fabricated with two types of metal-ceramic alloy, each type of alloy had 15 specimens. L*, a*, b* were measured after opaque porcelain was applied, and dentin porcelain was fired 1, 3, 5, 7 times by MINOLTA CR-100. Then delta E was calculated which reflected the color difference between high-gold alloy porcelain and Ni-Cr alloy porcelain.
RESULTSComparing with Ni-Cr alloy porcelain, the color of Au-Pt alloy porcelain was reddish, yellowish and less bright. The delta E between high-gold alloy porcelain and Ni-Cr alloy porcelain in shade A2 was largest when opaque porcelain was applied. It decreased when dentin porcelain was applied. It became smallest when fired 3 times, and increased along with the increase of fire times. It was larger than 1.5 except firing 3 times. When dentin porcelain was applied, delta E which was larger than 1.5 among different dentin porcelain thickness decreased along with the increase of dentin porcelain thickness.
CONCLUSIONThe color difference between the two types of metal-ceramic alloy should be carefully taken into account in order to improve the quality of color matching.
Chromium ; Chromium Alloys ; Dental Porcelain ; Dental Prosthesis Design ; Gold Alloys ; Humans ; Metal Ceramic Alloys ; Nickel ; Platinum ; Prosthesis Coloring
2.Cytotoxicity and physical properties of tricalcium silicate-based endodontic materials.
Young Eun JANG ; Bin Na LEE ; Jeong Tae KOH ; Yeong Joon PARK ; Nam Eok JOO ; Hoon Sang CHANG ; In Nam HWANG ; Won Mann OH ; Yun Chan HWANG
Restorative Dentistry & Endodontics 2014;39(2):89-94
OBJECTIVES: The aim of this study was to evaluate the cytotoxicity, setting time and compressive strength of MTA and two novel tricalcium silicate-based endodontic materials, Bioaggregate (BA) and Biodentine (BD). MATERIALS AND METHODS: Cytotoxicity was evaluated by using a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide (XTT) assay. Measurements of 9 heavy metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) were performed by inductively coupled plasma-mass spectrometry (ICP-MS) of leachates obtained by soaking the materials in distilled water. Setting time and compressive strength tests were performed following ISO requirements. RESULTS: BA had comparable cell viability to MTA, whereas the cell viability of BD was significantly lower than that of MTA. The ICP-MS analysis revealed that BD released significantly higher amount of 5 heavy metals (arsenic, copper, iron, manganese, and zinc) than MTA and BA. The setting time of BD was significantly shorter than that of MTA and BA, and the compressive strength of BA was significantly lower than that of MTA and BD. CONCLUSIONS: BA and BD were biocompatible, and they did not show any cytotoxic effects on human periodontal ligament fibroblasts. BA showed comparable cytotoxicity to MTA but inferior physical properties. BD had somewhat higher cytotoxicity but superior physical properties than MTA.
Cadmium
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Cell Survival
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Chromium
;
Compressive Strength
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Copper
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Fibroblasts
;
Humans
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Iron
;
Manganese
;
Metals, Heavy
;
Nickel
;
Periodontal Ligament
;
Spectrum Analysis
;
Water
;
Pemetrexed
3.A Study on the concentration of trace metal elements in whole blood of the women in reproductive ages in urban and rural area.
Korean Journal of Preventive Medicine 1984;17(1):95-106
To acquire the essential basic data to the establishment of control measure for the hazardous health effect that could be caused by harmful metals, the author measured the concentrations of trace metals in whole blood of women of 20-39 years old living in urban and rural area using atomic absorption spectrophotometer. The summarized results were as follows; 1. The mean concentration of zinc in whole blood was 10.69+/-8.07 microgram/ml in rural area. The frequency distribution by zinc concentration level was nearly L-type and the cumulative frequency distribution was showed bimodal type in both area. 2. The mean iron concentration in whole blood was 323.09+/-87.15 microgram/ml and 322.07+/-104.74 microgram/ml in urban and rural area, respectively. The frequency distribution was similar to normal distribution type in both area, but the cumulative distribution was unimodal type in urban area and bimodal type in rural area. 3. The mean magnesium concentration was 41.08+/-19.58 microgram/ml and 40.28+/-16.82 microgram/ml in the area, respectively. The frequency distribution type had skewness to the right and the cumulative frequency distribution was unimodal type in both area. 4. The mean copper concentration was 1.417+/-0.761 microgram/ml and 1.375+/-0.743 microgram/ml in the area, respectively. The frequency distribution type had skewness to the right and the cumulative frequency distribution was bimodal type in both area. 5. The mean manganese concentration was 0.079+/-0.039 microgram/ml and 0.07+/-0.058 microgram/ml in the area, respectively. The frequency distribution type had skewness to the right in both area but slight irregular in rural area and the cumulative distribution was unimodal and bimodal type in urban and rural area, respectively. 6. The mean cadmium concentration in whole blood was 0.031+/-0.026 microgram/ml in urban and 0.028+/-0.023 microgram/ml in rural area. The frequency distribution type had skewness to the right and cumulative frequency distribution was bimodal type in both area.
Absorption
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Cadmium
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Copper
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Female
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Humans
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Iron
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Magnesium
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Manganese
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Metals
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Zinc
4.Spatial assessment of soil contamination by heavy metals from informal electronic waste recycling in Agbogbloshie, Ghana.
Vincent Nartey KYERE ; Klaus GREVE ; Sampson M. ATIEMO
Environmental Health and Toxicology 2016;31(1):e2016006-
OBJECTIVES: This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. METHODS: A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination (Cdeg), we analyzed the individual contribution of each heavy metal contamination and the overall Cdeg. We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. RESULTS: Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall Cdeg. Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. CONCLUSIONS: Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and Cdeg, indicating soil contamination in AEPS with the nine heavy metals studied.
Agriculture
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Barium
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Burns
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Cadmium
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Chromium
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Cobalt
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Copper
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Electronic Waste*
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Fluorescence
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Ghana*
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Metals
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Metals, Heavy*
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Nickel
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Recycling*
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Soil*
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Spatial Analysis
;
United States Environmental Protection Agency
;
Zinc
5.Synthesis, structure characterization and anti-tumor activity of lanthanide complex Ln (Phen)2 (5-Fu)3 (NO3) (NO3 )2.
Wen-yuan ZHONG ; Zhi-xing HU ; Shun-fang CHEN ; Shu-yu JI ; Yi-ping ZHOU ; Ma-lin LI
Acta Pharmaceutica Sinica 2005;40(11):997-1000
AIMTo study the biochemistry of lanthanides, the cooperative action of inorganic and organic anti-tumor drugs.
METHODSA series of rare earth complexes were synthesized with Ln(NO3) 6H2O, Phen and 5-Fu. Their anti-tumor activity was measured by the improved MTT, SRB methods.
RESULTSThe formula of complex Ln[(Phen)2(5-Fu)3(NO3)](NO3)2(Ln = Y, La, Ce, Sm, Gd, Dy, Er; Phen = 1, 10-phenanthroline; 5-Fu = fluorouracil) was characterized by elemental analyses, molar conductivity, IR, TGA, and 13C NMR spectra. The preliminary biological activity studies indicated that Lanthanide complex has strong anti-tumor activity in vitro.
CONCLUSIONThe complex might have anti-tumor cooperation action.
Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cerium ; chemistry ; Drug Synergism ; Dysprosium ; chemistry ; Erbium ; chemistry ; Fluorouracil ; chemistry ; Gadolinium ; chemistry ; Humans ; Lanthanoid Series Elements ; chemistry ; Lanthanum ; chemistry ; Phenanthrolines ; chemistry ; Samarium ; chemistry ; Structure-Activity Relationship ; Yttrium ; chemistry
6.Studies on the mineral contents of some trematodes.
The Korean Journal of Parasitology 1965;3(3):73-85
The mineral contents of the adult Clonorchis sinensis from rabbits and human were measured, and its qualitative and semi-quantitative analyses were studied with 3.4 meter Ebert-Grating spectrograph, and its quantitative analyses were studied with Beckman DU spectrophotometer. The adult Clonorchis sinensis used in this study were divided into two groups, the first group was collected from the bile passage of the man (C. sinensis from man), the second group was collected from the bile passage of the rabbit(C. sinensis from rabbit). Simultaneously, spectrographic and photometric analyses were also performed on the adult worms of Paragonimus westermani. Furthermore, comparative spectrographic analyses of the trace elements were carried out on the C. sinensis from man, C. sinensis from rabbit, Fasciola hepatica, Eurytrema pancreaticum, and Paragonimus westermani, and the approximate contents of the trace elements of the above trematodes were compared with that of their host tissues and biles. The results obtained were as follows: In the spectrographic analyses of C. sinensis from man, sodium, phosphorus, potassium, copper, calcium, aluminum, iron, and magnesium were detected predominantly, and zinc, titanium, silicone, lead, manganese, barium, cromium, molybdenum, and silver were detected as trace elements. In the differences of level of the minerals in these two C. sinensis, copper level of C. sinensis from man was higher than that of C. sinensis from rabbit, while calcium level of the former worm was higher than that of the latter worm. The trace level of lead, molybdenum, and silver were acertained in the former, but latter were not detected . The contents of the minerals showed the characteristic features in each trematodes: the mineral of flukes in each host were much more than that of the others; such as copper in C. sinensis from man, calcium in the C. sinensis from rabbit, and silicone in the P. westermani. The vanadium was detected in the F. hepatica, E. pancreaticum, and P. westermani, while the other flukes were not detected. In the comparative spectrographic analyses of the trace elements among the trematodes and their host tissues and biles, the minerals which detected from flukes were also found in their tissues and biles of their host. But the mineral levels of C. sinensis from man, F. hepatica, E. pancreaticum, and P. westermani were higher than that of their host tissues and biles, except the C. sinensis from rabbit.
parasitology
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helminth
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trematoda
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C. sinensis
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rabbit
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Fasciola hepatica
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Eurytrema pancreaticum
;
Paragonimus westermani
;
biochemistry
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sodium
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phosphorus
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potassium
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copper
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calcium
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aluminum
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iron
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magnesium
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zinc
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titanium
;
silicone
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lead
;
manganese
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barium
;
cromium
;
molybdenum
;
silver
;
vanadium
7.Effect of gilding technique on the element release of beryllium ion from vera bond Ni-Cr-Be alloy.
Shu WANG ; Xin-min CHEN ; Lu PAN
West China Journal of Stomatology 2007;25(1):8-11
OBJECTIVETo evaluate the effect of gilding technique on the element release from Vera Bond Ni-Cr-Be alloy exposed to artificial saliva.
METHODSTo measure the quantity of beryllium ion which was released from common used Ni-Cr porcelain crown (controlling group), polished Ni-Cr porcelain crown (polished group), gilded Ni-Cr porcelain crown (gold-plating group) and gilded Ni-Cr porcelain crown prolonged 50% (gold-plating prolonged 50% group) in artificial saliva after 1 month, 3 months and 6 months by means of ICP-AES. So the effect of released beryllium ion with different treatments and the rule of different times with the same treatment were compared.
RESULTSThe quantity of released beryllium ion was statistic significant among different treatments. The quantity of released beryllium ion was gradually increased with the same treatment. At the end of this experiment, it was reached the highest. The speed of released beryllium ion was gradually decreased with the same treatment. At the end of this experiment it was reached the lowest.
CONCLUSIONThe gilding treatment can decrease the quantity of beryllium ion which released from Ni-Cr porcelain crown, and improve the biocompatibility.
Alloys ; Beryllium ; Chromium Alloys ; Crowns ; Dental Alloys ; Dental Porcelain ; Gold ; Humans ; Saliva, Artificial
8.Atmospheric Concentration of Heavy Metals of Pusan Area.
In Hyeok SONG ; Gyu Il CHO ; Deog Hwan MOON ; Chang Hee LEE ; Jung Hak KANG ; Jong Gab KIM ; Yong Soo HAN ; Chae Un LEE
Korean Journal of Preventive Medicine 1995;28(3):726-733
This study was carried out to assess the present level of atmospheric metals. Five metals-lead, cadmium, chromium, manganese, vanadium-were checked on the industrial(Sasang) and residental area(Daeshindong) in the city of Pusan sampling period was the year of 1986, 1990, and 1994, and the sampling time was 2 days of each site. As the result of comparison with the atmospheric standard of ASHRAE(1980) the average concentrations of lead was above the standard, the average concentrations of chromium was around the standard, and the average concentrations of cadmium and vanadium was below the standard. The average concentrations of manganese was above the standard of industrial environment. And the average concentrations of five metals was higher in the industrial area than the residental area The average concentrations of lead cadmium and chromium showed the increase tendency by the year, and the average concentrations of vanadium showed no change, and the average concentrations of manganese showed the decrease tendency. As a result of correlation analysis, lead and cadmium(r=0.31), vanadium and manganese(r=0.24), vanadium and chromium(r=0.19) showed significance.
Busan*
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Cadmium
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Chromium
;
Manganese
;
Metals
;
Metals, Heavy*
;
Vanadium
9.An Overview of Carcinogenic Heavy Metal: Molecular Toxicity Mechanism and Prevention.
Hyun Soo KIM ; Yeo Jin KIM ; Young Rok SEO
Journal of Cancer Prevention 2015;20(4):232-240
Almost all heavy metals are serious toxicants as carcinogens. However, due to their chemical and physiological properties, heavy metals are useful in industrial areas including alloy, smelting and production of commercial products. Such applications increase the opportunity for heavy metal exposure. Waste from industrial processes is also a major source of environmental contamination and accumulation in the human body. Arsenic, cadmium, chromium, and nickel are classified as group 1 carcinogens by the International Agency for Research on Cancer, and are utilized commercially. In this review, we used molecular pathway analysis to understand the toxicity and carcinogenic mechanisms of these metals. Our analyzed data showed that above-mentioned metallic substances induce oxidative stress, DNA damage, and cell death processes, resulting in increase the risk of cancer and cancer-related diseases. Thus, we might think phytochelatin molecules and antioxidative phytochemical substances are helpful for prevention of heavy metal-induced cancer.
Alloys
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Arsenic
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Cadmium
;
Carcinogens
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Cell Death
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Chromium
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DNA Damage
;
Human Body
;
International Agencies
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Metals
;
Metals, Heavy
;
Nickel
;
Osmeriformes
;
Oxidative Stress
;
Phytochelatins
10.Investigate some heavy metals concentration: lead, cadmium, arsenic and mercury at fresh water fish and snail in Hanoi markets
Journal of Vietnamese Medicine 2003;288(9):85-91
By atomic absorbance spectrophotometry, the content of heavy metals (lead, cadmium, arsenic, mercure) in freshwater fish and shelfish in the market and in 2 lakes in Hanoi from June to December 2002 was analysed. The contents are: lead 100%, arsenic 98.5%, cadmium 92.9% and mercury 88.6%, they are in the tolerable limits according to 1998 year Vietnam MOH regulation 867/BYT. The contents of various heavy metals are not similar in diverse genera of fish and shelfish. In some genera of fish, arsenic contents are higher than average from 0..68 to 0.601 mg/kg and mercury content 0.053mg/kg. Heavy metal contents in 2 lakes of Thanh Tri district and in diverse markets in Hanoi have not significant differences
Metals, Heavy
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Mercury
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Lead