消化终点对2·3—二胺基萘分子荧光法测定土壤中硒的影响

本文提出了消化终点对2·3—二胺基萘分子荧光法测定土壤中硒的影响,并试验了土壤试样,标准溶液和空白溶液消化的全过程,绘制了消化曲线,比较了三种试样的消化特点,讨论了消化终点的判断错误对测定准确度的影响及控制消化终点的方法.

Effects of hepatitis B virus infection on human sperm chromosomes

AIM: To evaluate the level of sperm chromosome aberrations in male patients with hepatitis B, and to directly detect whether there are HBV DNA integrations in sperm chromosomes of hepatitis B patients.METHODS: Sperm chromosomes of 14 tested subjects (5healthy controls, 9 patients with HBV infection, including 1with acute hepatitis B, 2 with chronic active hepatitis B, 4with chronic persistent hepatitis B, 2 chronic HBsAg carriers with no clinical symptoms) were prepared using interspecific in vitro fertilization between zona-free golden hamster ova and human spermatozoa, and the frequencies of aberration spermatozoa were compared between subjects of HBV infection and controls. Fluorescence in situ hybridization (FISH) to sperm chromosome spreads was carried out with biotin-labeled full length HBV DNA probe to detect the specific HBV DNA sequences in the sperm chromosomes.RESULTS: The total frequency of sperm chromosome aberrations in HBV infection group (14.8%, 33/223) was significantly higher than that in the control group (4.3%,5/116). Moreover, the sperm chromosomes in HBV infection patients commonly presented stickiness, clumping, failure to staining, etc, which would affect the analysis of sperm chromosomes. Specific fluorescent signal spots for HBV DNA were seen in sperm chromosomes of one patient with chronic persistent hepatitis. In 9 (9/42) sperm chromosome complements containing fluorescent signal spots, one presented 5 obvious FISH spots, others presented 2 to 4signals. There was significant difference of fluorescence intensity among the signal spots. The distribution of signal sites among chromosomes was random.CONCLUSION: HBV infection can bring about mutagenic effects on sperm chromosomes. Integrations of viral DNA into sperm chromosomes which are multisites and nonspecific, can further increase the instability of sperm chromosomes. This study suggested that HBV infection can create extensively hereditary effects by alteration genetic constituent and/or induction chromosome aberrations, as well as the possibility of vertical transmission of HBV via the germ line to the next generation.

Characterization and application of monoclonal antibodies against Shewanella marisflavi, a novel pathogen of Apostichopus japonicus

Shewanella marisflavi strain AP629 was certified as a novel pathogen of the sea cucumber Apostichopusjaponicus. In this study, four monoclonal antibodies （MAbs） （3C1, 3D9, 2F2, 2A8） against strain AP629 were developed by immunizing Balb/C mice. 3C1 and 3D9 recognized S. marisflavi only, showing no cross reactivity to other gram-negative bacteria, However, 2F2 and 2A8 showed cross reactivity to all tested bacteria. Indirect immunofluorescence, and immunogold electron microscopy, showed the binding antigens of 3C1 and 3D9 were located at the secretion on the surface of strain AP629. The binding antigens of 2F2 and 2A8 were noted on the membrane of the cells. MAbs 3C1 and 3D9 recognized the lipopolysaccharide fraction of strain AP629, and 2F2 and 2A8 recognized in western-blotting protein antigens with molecular weights of 113 and 128 kDa respectively. MAbs 3C1 and 3D9 have the potential for use in pathogen diagnosis, epidemiology and studies on the mechanism of how S. marisflavi infects A. japonicus. Imrnunohistochemistry with 3C1 or 3D9 identified strain AP629 in the body wall of infected A. japonicus. In the adult sea cucumbers that were infected via body wall injection, positive signals were observed at the site of skin ulceration, and at the connective tissue of the non-ulcerated body wall. In addition, some large blue-stained cells aggregated at the connective tissue colonized by large numbers of bacteria. In juveniles infected via immersion infection, positive signals were observed at the cuticle of the body wall only. Our results suggest that 3C1 and 3D9 could be used in various immunological assays to study the invasion mechanism of strain AP629 in A. japonicus, the law of bacterial colonization, proliferation in different tissues of A. japonicus, and correlation between secretion on the surface of strain AP629 and its pathogenesis to A. japonicus.

Distribution,fractionation,and contamination assessment of heavy metals in offshore surface sediments from western Xiamen Bay,China

Surface sediment samples were collected at 21 offshore sites in western Xiamen Bay, Southeast China. Total concentrations of Li, V, Cr, Co, Ni, Cu, Zn, St, Mn, Pb, Ba, Fe, and Ti were determined by inductively coupled plasma-optical emission spectrometry; Hg was determined by atomic fluorescence spectrometry. A modified BCR sequential extraction procedure was used to extract fractions of the above elements. Concentrations of Pb, Cr, and Hg at most sites met the primary standard criteria of Marine Sediment Quality except site S12 for Pb and S7 for Cr, while concentrations of Zn at 17 sites and Cu at seven sites exceeded the criteria. The mean concentration of Hg was three times higher than the background, with a possible source being the Jiulong River. Fe, Ti, Ba, Co, V, and Li dominated the residual phase, mainly from terrestrial input. Ni, Cr, Pb, and Hg in the non-residual phase varied largely between sites. Sr, Mn, Cu, and Zn were mainly in the non- residual fraction. Most sites showed considerable ecological risk; exceptions were site S7 （very high） and sites S10, S11, and S14 （moderate）. Cu showed moderate-to-high pollution and Pb exhibited no-to-low pollution, while other metals had a non-pollution status according to their ratios of secondary phase to primary phase （RSP）. Results of two assessment methods showed moderate pollution and a very high ecological risk for Cu, Zn, Ni, and Cr at site S7, which might be due to the local sewage treatment plant.

Determination of Chlorobenzene by Hydroxypropyl-β- Cyclodextrin Sensitized Fluorescence Quenching Method with Neutral Red as a Fluorescence Probe

The fluorescence quenching of inclusion complex of neutral red （NR） and hydroxypropyl-β-cyclodextrin （HP-β-CD） carried by chlorobenzene was investigated. The fluorescence intensity of NR increased due to the formed inclusion complex of HP-β-CD and NR. But the fluorescence intensity of NR-HP-β-CD diminished when chlorobenzene was added, and there was a linear relationship between the fluorescence quenching value of the system （△IF = IF, NR-HP-β-CD - IF, CB-NB-NR-HP-β-CD） and the concentration of chlorobenzene. Based on this, a novel fluorescence quenching method for the determination of chlorobenzene with NR as a fluorescence probe has been developed. Under the optimal conditions, the linear range of calibration curve for the determination of chlorobenzene was 5.0 × 10^-8 - 8.0 × 10^-6 mol/L and the detection limit was 1.0 × 10^-8 mol/L. It has been applied to determination ofchlorobenzene in synthetic waste water samples with satisfactory results.

Franck-Condon Factors and Band Origins for MgH in the A2П-X2∑＋ System

We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2∑＋（v＂=0,1） system by analyzing the experimental spectrum. Also, we calculate the Franck-Condon factors and transition frequencies of the A2H-X2∑＋ system of MgH. A comparison of our theoretical calculation and experimental results with other reported theoretical results was carried out as well.

Geochemical characteristics of illite clay rocks from the Shihezi Formation in the Hanxing mining area and its sedimentary environment

We studied the geochemical characteristics of illite clay rocks and their importance from the 5hihezi Formation of Late Permian in the Hanxing mining area by means of ICP-M5 and sequential X-ray fluorescence spectrometry. The results show that the amount of SiO2 is between 53.37% and 61.58% （by weight） and that of Al2O3 22.40% and 31.31% （by weight）. The ratio of SiO2/Al2O3 lies between 1.71 and 2.75. The amount of K2O ranges from 1.11% to 2.56% （by weight）. The amounts of Fe and Ti are higher than the theoretical values in illite clay rock would indicate. The amounts of some trace elements, such as Ga, As, Ba, Cu, Th and U are higher than their Clark values, while that of another 23 trace elements are found to be dose to their Clark values. The amounts of REE range from 22.59 to 570.54 μg/g, with an average of 163.23μg/g. The ratios of LREE/HREE range from 5.41 to 21.82, with an average of 8.87. These characteristics show that LREE are much richer in content than HREE. The REE distribution patterns of our samples were characterized by clearly negative Ce and Eu anomalies. We analyzed the sedimentary environment of the Hanxing mining area in Late Permian by the characteristic element ratio method. The ratios of Mn/Fe range from 0 to 0.0168, which are lower than those in a marine sedimentary environment. The ratios of Sr/Ba （0.20-0.41） are less than 1. These are all indications that the sediments of the Hanxing mining area in Late Permian form largely a continental sedimentary environment. The sedimentary water is freshwater, a conclusion reached on the basis of the ratios of Th/U （2.66-6.62） and of Ca/（Ca ＋ Fe） （0.01-0.059）; the average ratio of Fe2＋/Fe3＋ is 4.8. The sedimentary water condition is weakly acidic and weakly oxidative-weakly reductive, a conclusion reached on the basis of ratios of Fe2＋/Fe3＋ （4.8） and of Ceanom （-0.08）.

Prediction of XRF analyzers error for elements on-line assaying using Kalman Filter

Determination of chemical elements assay plays an important role in mineral processing operations.This factor is used to control process accuracy,recovery calculation and plant profitability.The new assaying methods including chemical methods,X-ray fluorescence and atomic absorption spectrometry are advanced and accurate.However,in some applications,such as on-line assaying process,high accuracy is required.In this paper,an algorithm based on Kalman Filter is presented to predict on-line XRF errors.This research has been carried out on the basis of based the industrial real data collection for evaluating the performance of the presented algorithm.The measurements and analysis for this study were conducted at the Sarcheshmeh Copper Concentrator Plant located in Iran.The quality of the obtained results was very satisfied;so that the RMS errors of prediction obtained for Cu and Mo grade assaying errors in rougher feed were less than 0.039 and 0.002 and in final flotation concentration less than 0.58 and 0.074,respectively.The results indicate that the mentioned method is quite accurate to reduce the on-line XRF errors measurement.