Distribution of ytterbium-169 in rat brain after intravenous injection.

It is well known that lanthanides have come into extensive and rapid use in a number of fields. As a result, more and more lanthanides are getting into the environment and food chains. However, the distributions of lanthanides in brain are not yet very clear.

Organohalogenated compounds in pine needles from Beijing city, China.

Pine needles collected from 22 sites of six areas in Beijing city, China, were analyzed by instrumental neutron activation analysis (INAA) combined with organic extraction for extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX). The concentrations of EOX (EOX = ECl + EOBr + EOI) were in the order of EOCl >> EOBr > EOI. About 1.

[Correlation of mercury, selenium and other elements in the tissues of fishes from the regions at different mercury exposure level].

The contents of selenium and other elements in fish liver and muscle tissues collected from mercury polluted area of Wanshan, Guizhou province of China and non-known mercury polluted one of Beijing were determined with instrumental neutron activation analysis, and that of mercury was determined with atomic fluorescence spectrometry. The correlation among the determined elements, especially between mercury and selenium, in the fish tissues were studied. For most of the elements significant difference of elemental content was found between tissues of liver and muscle, and mostly the content in liver was higher than that in muscle.

The cDNA and genomic DNA organization of a novel toxin SHT-I from spider Ornithoctonus huwena.

In present study the full-length cDNA of a novel toxin from the venom gland of spider Ornithoctonus huwena, named as SHT-I, has been cloned using the strategy of rapid amplification of cDNA ends, and then the whole genomic sequence of SHT-I (Selenocosmia huwena toxin-I) was determined using sequence-specific primers synthesized based on the acquired 3' and 5' ends of SHT-I cDNA sequence. It is unexpectedly found that intron was lacking in the genomic sequence of SHT-I. The result might evoke an interesting question whether the gene code of inhibitor cystine-knot peptides from spider venom is distinct from that of those known toxic peptides of scorpion and cone snail.

Element content and element correlations in Chinese human liver.

The amounts of the 19 elements As, Br, Ca, Cd, Ce, Co, Cr, Cs, Fe, K, La, Mo, Na, Rb, Sb, Sc, Se, Sm, and Zn in 92 lyophilized autopsy human liver samples from normal subjects have been analyzed by instrumental neutron-activation analysis (INAA). For intercomparison and quality control ten samples were independently analyzed in two institutes, the Institute of High Energy Physics in China and the "Jozef Stefan" Institute in Slovenia. Most of the element contents determined by the two institutes were in quite good agreement, even though different experimental conditions were applied, indicating the reliability of the analytical results.

Highly selective and simple synthesis of C(2)(m)--X--C(2)(n) fullerene dimers.

Energetic-radiation-induced dimerization reaction of fullerenes was found to be a simple and highly selective method for synthesis of C2m-X-C2n (m = n or m not equal n) type molecules without formation of other products. Utilizing the new method, C70-C-C70, C60-C-C70, C60-C-C60, and C70-O-C70 were prepared and characterized. The method is capable of synthesizing new C2m-X-C2n molecules by introducing X (different atoms) into the reaction system.

Mercury and trace element distribution in organic tissues and regional brain of fetal rat after in utero and weaning exposure to low dose of inorganic mercury.

Since it is still absent data about the toxic risk of low dose, especially an environmentally relevant dose of mercury to fetus after their prenatal exposure, this present work was designed to investigate the metabolism of Hg and its effect on the levels of essential trace elements in the organic tissues and the brain regions of infant rats after their exposure to environmentally relevant low dose of Hg(II) during the whole pregnant and weaning period. The pregnant female rats were exposed to a very low dose of 0.2 microg Hg2+/ml (as HgCl2, 12 rats/group) in drinking water from prenatal day 0 continued to postnatal day 20.

Influences of Structural Properties on Stability of Fullerenols.

Influences of structural properties on the stability of fullerenols are studied using experimental techniques including laser-induced dissociation associated with a time-of-flight measurement, synchrotron radiation XPS, and FT-IR spectroscopy. Stabilities of a family of fullerenols (C(OH), C(OH), C(OH), C(OH), C(OH), and C(OH)) as functions of structural parameters-the hydroxyl number, intensity of the impure group, and the ratio of the carbonyl to hydroxyl groups-are investigated. It is found that the molecular stability largely depends on the quantity of impure groups, especially the highly oxygenated carbons in fullerenols, but less on the hydroxyl number.

Study of trace elements in blood of thyroid disorder subjects before and after 131I therapy.

Both trace elements and thyroid hormones play essential roles in the human body. However, the previous results about the interaction between these two factors are often controversially given. In order to make clear the influence of thyroid hormones on the homeostasis of trace elements, we studied the variation of Fe, Cu, and Zn in erythrocyte and serum from patients with hyperthyroidism before and after 131I therapy by the X-ray fluorescence method.

Regional distribution of organochlorinated pesticides in pine needles and its indication for socioeconomic development.

The regional distribution of 10 potentially harmful organochlorinated pesticides (OCPs) was investigated in pine needles from 18 sites in six Chinese regions. The OCPs concentrations in six regions were as follows: sigmaHCH (sigmaHCH=alpha-+beta-+gamma-+delta-HCH), 4.7-51.

Suppressive effects of BmK IT2 on nociceptive behavior and c-Fos expression in spinal cord induced by formalin.

In this study, the suppressive effects of BmK IT2, a kind of Na+ channel-specific modulator from the venom of the scorpion Buthus martensi Karsch, on biphasic nociceptive behavior in rats and c-Fos expression in rat spinal cord induced by formalin were investigated. Fifty microliters of 2.5% formalin were subcutaneously injected into the rat hind paw; 0.

[Study on the microdischarge in dielectric barrier discharge by optical method].

The global light emission of dielectric barrier discharge with pattern mode in air was measured and compared with the global current obtained with a small resistor. The results show that the moments and the amplitudes of the pulses in light emission correspond to those in the global current, respectively. So the discharge current can be measured by optical methods.

[Temporal behavior of light emission of dielectric barrier discharges in air at atmospheric pressure].

The experimental setup of dielectric barrier discharge was designed which is propitious to optical measurement. Temporal behavior of light emission of dielectric barrier discharges (filamentary model) in air at atmospheric pressure was measured by using optical method. Temporal behavior of dielectric barrier discharges was obtained.

Variations of elemental distribution in brain regions of neonatal rats at different iodine intakes.

Iodine deficiency (ID) can result in irreversible damage to the brain during the fetal and neonatal stages. As the active center of many enzymes, trace elements play essential roles in brain function. In this work, the relative contents and distributions of elements (Cl, Br, Fe, Cu, and Zn) in two important brain regions, the cerebral cortex and hippocampus, of the iodine-deficient model rats were determined by the synchrotron radiation X-ray fluorescence (SRXRF) method.

2001 survey of organochlorine pesticides in retail milk from Beijing, P R China.

A monitoring study was conducted in 2001 to determine the organochlorine pesticides and their metabolite residues in milk taken from supermarkets in Beijing, P. R. China.

Study of chromium-containing proteins in subcellular fractions of rat liver by enriched stable isotopic tracer technique and gel filtration chromatography.

Ten male Wistar rats were intravenously injected with a single approximately physiological dose of enriched stable isotopic Cr-50 tracer solution (200 ng (50)Cr(3+)/100 g body wt). The fundamental distribution patterns of the chromium-containing proteins in the nucleic, mitochondrial, lysosomal, microsomal, and cytosolic subcellular fractions of the rat liver were investigated by means of Sephadex G-100 gel chromatography combined with neutron activation analysis via (50)Cr (n, gamma) (51)Cr reaction. In total, nine kinds of Cr-containing proteins were found in the five subcellular fractions, whose relative molecular masses were 96.

Levels of extractable organohalogens in pine needles in China.

Pine needles can accumulate organohalogens from the ambient air, which are, hence, able to serve as a biomonitor to evaluate the levels of organochlorinated contaminants in the atmospheric environment. Extractable organochlorine (EOCl), the most abundant of the extractable organohalogens (EOX) in environmental samples, has received much attention as a parameter for evaluation of total contamination levels of organochlorinated compounds (OCs). However, few data concerning EOCl in vegetation are available.

Detection of metalloproteins in human liver cytosol by synchrotron radiation X-ray fluorescence combined with gel filtration chromatography and isoelectric focusing separation.

Synchrotron radiation X-ray fluorescence (SRXRF) spectroscopy is an advanced method of quantitative multielemental analysis with space resolution of several microm and sensitivities in the microg g(-1) range. It can be used for keeping track of trace elements after an electrophoretic separation of biological samples. In this paper, proteins in human liver cytosol were separated with gel filtration chromatography and thin layer isoelectric focusing (IEF).

Activable enriched stable isotope iron-58 for monitoring absorption rate of juvenile athletes for iron: a case study.

Activable enriched stable isotopes can play a unique role in studies of nutritional status, metabolism, absorption rates, and bioavailability of minerals. As a practical example, eight juvenile athletes were selected to test the absorption rates of iron during training and non-training periods by enriched stable isotope of Fe-58 (enriched degree: 51.1%) via activation analysis Fe-58 (n, gamma) Fe-59 of the collected feces samples.

Speciation and subcellular location of se-containing proteins in human liver studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and hydride generation-atomic fluorescence spectrometric detection.

Speciation of Se-containing proteins in the subcellular fractions of human liver was studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by hydride generation-atomic fluorescence spectrometric (HG-AFS) detection. It was found that about 24 kinds of Se-containing proteins existed in subcellular fractions of normal human liver. The molecular weights (MW) of the subunits were mostly in the range 20-30 kDa and 50-80 kDa.

Overview of the methodology of nuclear analytical techniques for speciation studies of trace elements in the biological and environmental sciences.

Recent achievements in speciation studies of trace elements in the biological and environmental sciences by nuclear analytical techniques, mainly molecular activation analysis, position-sensitive spectrometry with a variety of exciting sources, and synchronous radiation-based analytical techniques (although radioisotope or enriched stable isotope-based speciation techniques are also used), particularly in our laboratory, are outlined. In this paper the merits and drawbacks of the nuclear analytical techniques are discussed, as are reagent blanks, contamination, and artifacts.