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  • Author or Editor: C. Kim x
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Abstract  

The concentrations of3H,137Cs and239,240Pu were determined in surface seawaters collected at 21 sampling stations around Korea from October of 1994 to May of 1995. The results were consistent with the past data observed in the North Pacific. The concentrations of3H and137Cs did not show much difference no matter where the samples were taken. Due to the limited distribution of sampling points, no systematic change in3H and137Cs levels with latitude was observed. On the other hand,239,240Pu concentration in the East Sea (Japan Sea) was somewhat higher than that in the South and the Yellow Seas, although the data on239,240Pu concentration were not enough to explain the reason. The activity ratios of239,240Pu/137Cs in surface seawater ranged from 0.13% to 0.44% with a mean of 0.25±0.08%. The activity ratios were lower than those of the global fall-out level, 1.1%. This result presumably arose from the different behavior of the two radionuclides in seawater.

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Abstract  

The novel N4S2 azacrown ion exchange resin was prepared. The ion exchange capacity of N4S2 ion exchanger was 0.34 meq/g dry resin. A study on the separation of lithium isotopes was carried out with N4S2 azacrown ion exchange resin. The lighter isotope,6Li is concentrated in the resin phase, while the heavier isotope,7Li is enriched in the solution phase. With column chromatography [0.1 cm (I.D.)×32 cm (height)] using 2.0M NH4Cl as an eluent, separation factor, a=1.034 was obtained.

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Abstract  

The elution chromatographic separation of magnesium isotopes was investigated by chemical ion exchange with the synthesized 1,7-dioxa-4,10,13-triazacyclopentadecane-4,10,13-trimerrifield peptide resin [N3O2·3M]. The capacity of novel N3O2 azacrown ion exchanger was 0.21 meq/g dry resin. The heavier isotopes of magnesium concentrated in the resin phase, while the lighter isotopes are enriched in the solution phase. The glass ion exchange column used in our experiment was 30 cm long with inner diameter of 0.2 cm, and the 2.0M NH4Cl solution was used as an eluent. The separation factors of 24Mg-25Mg, 25Mg-26Mg, and 24Mg-26Mg were 1.030, 1.009, and 1.027, respectively.

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Abstract  

The chromatographic separation of magnesium isotopes was investigated by chemical ion exchange with 1,16-dithia-4,7,10,13-tetraazacyclooctadecane-4,7,10,13-tetramerrifield peptide resin[N4S2·4M] synthesized recently. The capacity of novel N4S2 azacrown ion exchanger was 0.34 meq/g dry resin. The heavier isotopes of magnesium concentrated in the resin phase, while the lighter isotopes are enriched in the solution phase. The glass ion exchange column used was 30 cm long with inner diameter of 0.2 cm, and the 1.0M NH4Cl solution was used as an eluent. The separation factors of24Mg−25Mg,25Mg−26Mg, and24Mg−26Mg were 1.047, 1007, and 1.008, respectively.

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Abstract  

A study on the separation of lithium isotopes was carried out with 1,13-dioxa-4,7,10-triazacyclopentadecane-4,7,10-trimerrifield peptide resin [N3O23M]. The resin having N3O2 as an anchor group has a capacity of 0.2 meq/g dry resin. Upon column chromatography [0.1 cm (I.D)×30 cm (height)] using 1.0M NH4Cl solution as an eluent, a single separation factor of 1.00104 was obtained from the elution curve and isotope ratios based on theGlueckauf theory. The heavier isotope,7Li concentrated in the resin phase, while the lighter isotope,6Li enriched in the solution phase.

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Abstract  

239+240Pu concentrations and 240Pu/239Pu atom ratios in bottom sediments of the Yellow Sea, Korea Strait, East Sea (Sea of Japan), Sea of Okhotsk, and Northwest Pacific Ocean were determined. In coastal sediments near the Korean Peninsula, 239+240Pu concentrations varied from 0.02 to 1.72 Bq.kg-1, and their 240Pu/239Pu atom ratios from 0.15 to 0.24, with an average of 0.20±0.03. 240Pu/239Pu atom ratios of bottom sediments in the deep NW Pacific Ocean and its marginal seas (East, Okhotsk seas) were in the range of 0.15-0.23. A little elevated 240Pu/239Pu atom ratios in the bottom layer sediment may be due to Pu released into the environment during the pre-moratorium period, having high 240Pu/239Pu atom ratios and low 238Pu/239+240Pu activity ratios.

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Abstract  

High resolution inductively coupled plasma mass spectrometry coupled with an on-line flow injection system (FI-HR-ICP-MS) was applied to determine the ultra-trace level 99Tc in soil. The flow injection system (PrepLab) was composed of two TEVA-SpecÒresins, reduced remarkably the sample amounts and the analysis time, compared to the conventional analytical methods. In the flow injection system, Mo and Ru were sufficiently eliminated by using the flow injection system, with the decontamination factors of 1.6.104 and 9.9.105, respectively. With the present method, it was possible to determine ultra-low level of 99Tc in 3-6 g soil at 3–5 hours of analysis time per sample. The relative standard deviation for each sample was less than 4%. The detection limits for 99Tc was 85 fg.ml–1 (0.05 mBq.ml–1), which was calculated from the three times standard deviation of the count rate of the blank.

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Abstract  

The present plutonium levels in the Pacific Ocean are summarized. The 239,240Pu concentrations in surface seawaters in the early 2000s were in the range of 1.5 to 9.2 mBq·m−3 in the North Pacific and 0.8 to 4.1 mBq·m−3 in the South Pacific. There is no marked difference of surface 239,240Pu distributions between the North and South Pacific subtropical gyres. The vertical profile of 239,240Pu in the South Pacific was the similar pattern to that in the North Pacific, which is controlled by biogeochemical processes. The 239,240Pu inventories (down to 2300 m) in the North Pacific are generally greater than that in the South Pacific, which reflects the geographical distribution of global fallout and effect of close-in fallout in the Marshall Islands.

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Background

A substantial number of people worldwide suffer from mental health problems during their lifetime. First-line treatments are not effective for everybody. Recent studies suggest that psychedelic drugs have high therapeutic potential for a variety of mental disorders.

Aims

This survey study aimed to assess the tendency of psychedelic users to self-medicate with psychedelics and to compare the effectiveness of self-administered psychedelics to treat their disorder and the treatment offered by a medical professional.

Methods and results

In total, 1,967 respondents consented were ≥18 years and completed the questionnaire. The mean (±SD) age was 25.9 (8.7); 79% were males, 20% females, and 1% classified themselves as “other.” Almost half of the respondents (46%) indicated to have suffered/to be suffering from a mental disorder, with 77% being diagnosed by a medical professional. In 99% of the diagnosed cases, the treatment was offered; 77% searched for treatments outside a medical professional’s recommendation with 81% who had used/were using psychedelics to treat/cure symptoms. Self-administered psychedelic treatment had a higher likelihood of being efficacious, with higher symptoms reduction and larger quality of life improvement compared to treatment offered by a medical professional.

Conclusions

Lifetime prevalence of psychopathologies in the current sample of psychedelic drug users seemed to be higher than in the general population. Self-medication with psychedelics was not highly frequent; although when it occurred, it was rated as significantly more effective as treatment offered by a medical professional. Current findings support research exploring the potential of psychedelics in the treatment of psychopathologies.

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