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1.
Instrumental neutron activation (INAA) with k 0 standardization has been used to determine the concentration levels of a variety of major and trace elements (Al, As, Br, Cd, Cl, Co, Cr, Cs, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Rb, Sc, Se, and Zn) in rice grains (raw and parboiled) and in rice flour collected from local markets in Sri Lanka. In addition, the energy-dispersive X-ray fluorescence (EDXRF) analysis has been used to determine the three elements Ca, P, and S in powdered samples. To evaluate and assure the accuracy and precision of the k 0 standardization method, the IAEA standard reference material V-8 rye flour was analyzed. The results obtained in the present investigation were compared with the results reported from other countries. All of the elements detected in the rice matrices from Sri Lanka were very low in concentration or within normal limits for food plants. Approximate daily dietary intakes of the individual elements supplied through rice were calculated and compared with the available literature values of daily allowances.  相似文献   

2.
The advantages and disadvantages of neutron activation analysis (NAA) and inductively coupled plasma-source mass spectrometry (ICP-MS) for the analysis of biological materials is reviewed. Comparison is made between NAA (instrumental) and ICP-MS (conventional pneumatic solution nebulization and laser ablation) analysis of the biological reference material National Bureau of Standards (NBS) SRM 1577 Bovine Liver. Relatively good agreement is achieved between the results for the 18 elements analyzed by both techniques and those either certified or reported in the literature. Elemental concentrations for Li, Mg, Al, Ca, Cr, Mn, Fe, Cu, Zn, Br, Rb, and Cs are also reported for IAEA Mixed Human Diet (H9), NBS SRM 909 Human Serum, and NBS SRM 1577a Bovine Liver, analyzed by solution nebulization ICP-MS.  相似文献   

3.
A research program related to the assessment of toxic heavy metals and essential trace elements in foodstuffs has been carried out in 12 countries under the auspices of the IAEA. The main purpose of this program was to obtain data on the elemental concentrations of potentially toxic elements in foodstuffs in various countries, and to compare them with the maximum permissible levels specified in national legislation and international guidelines. High-priority elements for this study were As, Cd, Cr, Pb, Hg, and Se. Also of interest, but of lower priority, were Sb Cu, and Zn/ Emphasis was placed on the use of nuclear and nuclear-related analytical techniques, complemented by conventional methods, and on quality assurance.  相似文献   

4.
The Asia and the Pacific region was within the IAEA program on radiation and tissue banking, the most active region. Most of the tissue banks in the Asia and the Pacific region were developed during the late 1980s and 1990s. The initial number of tissue banks established or supported by the IAEA program in the framework of the RCA Agreement for Asia and the Pacific region was 18. At the end of 2006, the number of tissue banks participating, in one way or another in the IAEA program was 59. Since the beginning of the implementation of the IAEA program in Asia and the Pacific region 63,537 amnion and 44,282 bone allografts were produced and 57,683 amnion and 36,388 bone allografts were used. The main impact of the IAEA program in the region was the following: the establishment or consolidation of at least 59 tissue banks in 15 countries in the region (the IAEA supported directly 16 of these banks); the improvement on the quality and safety of tissues procured and produced in the region reaching international standards; the implementation of eight national projects, two regional projects and two interregional projects; the elaboration of International Standards, a Code of Practice and a Public Awareness Strategies and, the application of quality control and quality assurances programs in all participating tissue banks.  相似文献   

5.
This paper describes the role of the Polish Secondary Standard Dosimetry Laboratory (SSDL) in quality assurance in radiotherapy by means of providing calibration of ionisation chambers, TLD postal dosimetry audits and end-to-end audits for radiation therapy. A historical review of the methods and results are presented. The influence of the SSDL in Warsaw on radiation protection of patients in Poland is discussed. The International Atomic Energy Agency together with World Health Organisation (IAEA/WHO), through its network of SSDLs around the world, propagates newly developed methods for calibration and auditing. Suitable high quality equipment was provided by the IAEA, as well as special materials and technical support to the SSDL in Warsaw. The activity of the SSDL and the services provided for Polish radiotherapy centres have resulted in a reduction of discrepancies between planned doses and doses delivered to patients. The newly tested IAEA methods of end-to-end on-site dosimetry audits allow for monitoring and improving the quality of IMRT in Poland. The traceability of standards used for the calibration of therapy level dosimeters from Polish radiotherapy centres is assured by the IAEA dosimetry laboratory. The consistency of methods performed in the Polish SSDL with the ISO:17025 norm is supervised by the Polish Centre for Accreditation – a member of International Laboratory Accreditation Cooperation (ILAC), for calibration and testing. Due to the rapid technological development of radiotherapy, special attention has to be paid to newly developed methods for dosimetry auditing and institutions which provide services for assuring radiation safety of patients.  相似文献   

6.
Elemental analysis of soils from two different arable regions in Libya was carried out to measure the level of many trace elements. Instrumental neutron activation analysis was used for the determination of 10 elements, viz., (Ba, Ce, Co, Cr, Cs, Fe, Sc, Se, Th, and Zn), using their long-lived radionuclides. The accuracy of the measurements has been evaluated by analyzing two IAEA soil reference materials: IAEA Soil-7 and IAEA leak sediment SL-1; precision has been estimated by triplicate analysis of the sample and that of the reference material. Irradiations were carried out at the Tajura Research Center reactor, at 5-MW power level. It is clear that in the Libyan soil selenium concentration is somewhat lower than in other countries. The results show that trace metal concentrations in Libyan clay surface soil are higher than the sandy soil.  相似文献   

7.
Vanadium was determined by radiochemical neutron activation analysis (RNAA) with proven accuracy in urine of workers occupationally exposed to vanadium-rich dust in a vanadium pentoxide production plant, and values in the range of 3.02–762 ng/mL (median 33.0 ng/mL) were found. In a control group consisting of administrative workers of the plant, urinary vanadium levels were found in the range of 1.05–53.4 ng/mL (median 2.53 ng/mL), whereas in an another control group of occupationally nonexposed persons, these values amounted to 0.066–0.489 ng/mL (median 0.212 ng/mL). Accuracy of the results was tested by analysis of reference material IAEA A-13 Animal Blood and NIST SRM-1515 Apple Leaves, and very good agreement was found with literature and the NIST certified values, respectively. Unlike urine, no significant differences were found for cystine levels in fingernails and hair of exposed and control persons.  相似文献   

8.
Since 1992, the International Atomic Energy Agency (IAEA) has been promoting studies of air pollution using a standard design of air sampler that provides separation on filters into two size fractions with cutoffs of 2.5 and 10 Μm (approximately). These are the size ranges presently considered to have the most important health consequences. Such filter samples are highly amenable to analysis using nuclear and related techniques. After reviewing some of the health effects of airborne particulate matter and current air quality standards and guidelines, this article provides an overview of current and recent IAEA programs in this area, which involve collaborative activities with participants in more than 40 countries.  相似文献   

9.
Since 1993, the IAEA supported the establishment or the consolidation of seven tissue banks in the region. As a direct or indirect consequence of the implementation of the IAEA program, more than 53 tissue banks are now operating in the participating countries. The fast development of tissue banks in the Latin America region under the ARCAL Agreement and with the financial and technical support of the IAEA program made it necessary to train new tissue bank operators and medical personnel. In general, 90 tissue bank operators and medical personnel were trained in the training centre of Buenos Aires. Another six tissue bank operators and medical personnel were trained in the International Training Centre of Singapore. The main impact of the IAEA program in the region was the following: the establishment or consolidation of fifty-three tissue banks in nine countries in the region; the implementation of five national projects, allocating $1,006,737 dollars for this purpose and of one regional project allocating $284,741 dollars for this purpose; the use of the IAEA Standards, the IAEA Code of Practice and the IAEA Public Awareness Strategies in several tissue banks in the region; the application of quality control and quality assurances manuals in all of the participating countries.  相似文献   

10.
以橡胶草为试验材料,利用农杆菌介导法进行遗传转化研究。结果表明:50 mg/L的卡那霉素(Kan)对橡胶草的抗性芽具有很好地筛选效果,生根筛选时,Kan的适宜质量浓度为35 mg/L;最佳抑菌抗生素为羧苄青霉素(cb),适宜质量浓度为500 mg/L,获得35株抗性试管苗,通过GUS染色及分子生物学检测,最终获得6株转基因植株,转化率为17.1%。可见,获得的橡胶草转基因植株,为橡胶草后续的遗传转化研究奠定了基础。  相似文献   

11.
Under the auspices of the IAEA tissue banking programme on “Radiation Sterilisation of Tissue Graft” conducted from 1985 to 2004, many scientists and surgeons were involved in various regional research and development (R&D) projects mainly in dealing with radiation dose selection, radiation effects on human tissues and quality system in radiation sterilisation. New findings on radiation effects, tissue processing and preservation were shared during the regional and interregional meetings and workshops. Many tissue banks started to use radiation (25 kGy) to sterilize tissue grafts for tissue safety and efficacy and still continue to use it. The IAEA Code of Practice for Radiation Sterilization of Tissues Allografts developed in 2007 offered simpler methods to conduct radiation dose setting and dose validation experiments for tissue grafts. Advances in dose selection and dose mapping are continued under the quality management system when banks need to be certified to continue their operation. The combination of good tissue processing and preservation as well as good radiation practice will ensure the tissue products are properly sterilised thus safe and of high quality. Experience in meeting challenges in using radiation sterilisation and achievements reported by the tissue bankers are shared here.  相似文献   

12.
Summary Differences in N2-fixation byPhaseolus vulgaris bean cultivars were successfully evaluated in the field using15N isotope dilution technique with a non-fixing test crop of a different species (wheat). The Phaseolus cultivars could have been similarly ranked for N2-fixation capacity from either seed yield or total nitrogen yield, but the isotope method provided a direct measure of N2-fixation and made it possible to estimate the proportion of fixed to total nitrogen in the crop and in plant parts. Amounts of nitrogen fixed varied between 24.59 kg N/ha for the 60-day cultivar Goiano precoce to 64.91 kg N/ha for the 90-day cultivar Carioca. The per cent of plant nitrogen due to fixation was 57–68% for the 90-day cultivars and 37% for Goiano precoce (60-day cultivar). Fertilizer utilization was 17–30% of a 20 kg N/ha fertilizer application. 100 kg N/ha fertilizer application decreased N2-fixation without suppressing it totally. Differences in yield between the highest yielding (Carioca) and the lowest (Moruna) 90-day cultivars were also due apparently to varietal differences in efficiency of conversion of nitrogen to economic matteri.e. seed, as well as to differences in capacity of genotypes for N2-fixation. The work described here was in part supported by IAEA Research Contract No. RC/2084 UNDP/IAEA Project BRA/78/006  相似文献   

13.
Commonly used methods for extraction of RNA from plants are not effective for isolation of high quality RNA from the pigmented seed coats of soybeans that produce procyanidins (tannins) during seed coat development. We demonstrate a significant modification of the phenol-LiCl method that yields high quality RNA from a black seed coat variety. In this method, seed coat material was ground in a buffer containing a high concentration of bovine serum albumin (100 mg BSA/50 mg of lyophilized seed coats) to competitively inhibit proanthocyanidin binding. The presence of hydrated insoluble polyvinylpoly-pyrrolidone (PVPP) was also necessary to bind proanthocyanidins and remove them from solution. Proteinase K was added to digest the remaining BSA, and phenol extraction was used to remove both the proteins and small molecular weight complexes formed by BSA and proanthocyanidins. After LiCl and ethanol precipitations, the RNA quality was examined by UV absorbance spectra, gel electrophoresis, and hybridization. Using this method, good quality RNA can be extracted from pigmented seed coats of soybean varieties that are homozygous for the recessivei allele and also contain the dominantT gene that results in production of procyanidins in the seed coat. The method is also effective for tissues from other plant species that contain abundant polyphenolic compounds.  相似文献   

14.
糖基转移酶广泛存在于植物中,其中UDP依赖型糖基转移酶(UDP-glycosyltransferases,UGTs)基因家族是糖基转移酶中的一大类。该研究以华南124木薯品种(Manihot esculenta cv.SC124)为材料,利用RT-PCR技术克隆木薯MeUGT41基因,以病毒诱导干扰木薯MeUGT41基因的表达量,并对基因干扰植株进行细菌性枯萎病抗性评价,为研究MeUGT41基因在木薯抵抗细菌性枯萎病的抗病机理奠定基础。结果表明:(1)地毯草黄单胞菌(Xamthomonas axonopodis pv.Manihotis,Xam)可显著诱导木薯MeUGT41基因表达。(2)成功构建MeUGT41的病毒诱导基因沉默(VIGS)载体,将干扰载体转化至木薯叶片进行MeUGT41基因沉默,荧光定量PCR检测结果显示,木薯叶片中MeUGT41基因的表达量显著下降。(3)Xam侵染实验表明,干扰抑制MeUGT41基因表达可显著降低木薯植株叶片对Xam病菌侵染的抵抗能力。研究认为,木薯叶片中MeUGT41基因具有抵抗Xam病菌侵染的能力。  相似文献   

15.
不同品种来源广藿香叶表皮毛特征比较分析   总被引:1,自引:0,他引:1  
叶表皮毛特征作为药用植物的"微性状"特征,被越来越多地应用于植物学分类研究中,表皮毛的生长发育状态可以直接影响药材的整体品质。广藿香主要含有挥发油成分,叶表皮毛中的腺毛是其挥发油的主要合成分泌场所,而非腺毛可以起到保护作用,影响其长势和产量。为了探讨叶表皮毛特征在广藿香品种鉴别方面的意义,该研究以8个不同品种来源以及2个采收期(6月末和10月末)的广藿香的顶叶、第4对生叶及底叶为材料,采用水合氯醛透化法制片,于光学显微镜下观察拍照,使用Microsoft Excel 2019统计数据,采用SPSS 23.0统计学软件对叶表皮毛密度、腺毛直径进行方差分析、主成分分析和聚类分析。结果表明:同一品种来源,不同采收期的广藿香叶表皮毛密度有显著性差异,6月末采收的广藿香叶表皮毛密度显著低于10月末采收的;根据叶表皮毛(非腺毛、头状腺毛、盾状腺毛)密度及腺毛直径,可将相同采收期的8个不同品种来源广藿香分为4类,且可以将已知品种来源的南香、肇香和牌香分开,与传统分类结果有着很好的一致性。叶表皮毛密度和腺毛直径在广藿香的分类中具有一定的参考意义,并为广藿香药材品质形成机制的研究提供参考。  相似文献   

16.
Summary Incubation of 25 and 30 day old nodulated plants ofPhaseolus vulgaris for periods of 24 h and 72 h under 15-dinitrogen atmosphere indicated nitrogen enrichment of soil compared with soil free of plants and with other plants under the same experimental conditions. This indication of release from the root-nodule system is discussed.UNDP/IAEA/Project BRA/71/556-CENA.  相似文献   

17.
The biomechanics of body contraction in Porifera is almost unknown, although sponge contraction has been observed already in ancient times. Some members of the genus Tethya represent the most contractile poriferan species. All of them show a highly ordered skeleton layout. Based on three main spicule types, functional units are assembled, termed skeleton superstructures here. Using synchrotron radiation based x-ray microtomography and quantitative image analysis with specially developed particle and structure recognition algorithms allowed us to perform spatial allocation and 3D-morphometric characterizations of single spicules and skeleton superstructures in T. minuta. We found and analyzed three skeleton superstructures in the investigated specimen: (1) 85 megasclere bundles, (2) a megaster sphere, composed by 16,646 oxyasters and (3) a pinacoderm–tylaster layer composed by micrasters. All three skeleton superstructures represent composite materials of siliceous spicules and extracellular matrix. From structure recognition we developed an abstracted mathematical model of the bundles and the sphere. In addition, we analyzed the megaster network interrelation topology and found a baso-apical linear symmetry axis for the megaster density inside the sphere. Based on our results, we propose a hypothetical biomechanical contraction model for T. minuta and T. wilhelma, in which the skeleton superstructures restrain physical stress generated by contraction in the tissue. While skeletal structures within the genus Tethya have been explained using R. Buckminster Fullers principle of tensegrity by other authors, we prefer material science based biomechanical approaches, to understand skeletal superstructures by referring to their composite material properties.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at .  相似文献   

18.
The endemic New Zealand red alga Gigartina atropurpurea has been identified as a candidate for aquaculture because of its high quality and value carrageenan and its broad-bladed morphology. As G. atropurpurea has not so far been exploited commercially, trials were conducted to investigate the effect of timing and frequency of pruning on the growth of plants in the wild and explants on ropes, in spring, and autumn. Plants were monitored monthly by measuring the length of the two longest blades (a proxy for biomass) and wet weights of all plant material retrieved. The results suggested five broad conclusions: (1) spring growth was much greater than autumn growth; (2) regardless of season, maximal growth rates were achieved 4–6 weeks post pruning; (3) pruning accelerated growth; (4) pruning plants twice during spring generated up to four times more biomass than when plants were pruned only once, and (5) there was no difference in the response of farmed and wild plants to pruning treatments. Based upon these preliminary trials, plant material from wild tetrasporic and female G. atropurpurea could be harvested up to three times during the growth period (August–December). However, further research on the feasibility of G. atropurpurea aquaculture is justified.  相似文献   

19.
Synopsis The dietary composition and the nutritional status and the digestibility of the diets of Sarotherodon mossambicus from nine reservoirs in Sri Lanka were evaluated. The feeding habits of S. mossambicus were variable from reservoir to reservoir; they ranged from herbivory to total carnivory. The protein, total lipid, carbohydrate and total organic matter content of the ingested material were related to the dietary composition and ranged from 18.53% to 35.15% (x−24.18%), 5.94% to 9.84% (x−7.91%), 11.6% to 34.7% (x−22.34%) and 34.4% to 64.4% (x−45.71%), respectively. Irrespective of the feeding habits, the diet contained a significant proportion of organic material which cannot be accounted for by protein, total lipid and carbohydrate. As much as the ingested material was related to the feeding habit, the digestibility of the nutrient components was related to the food material devoured. For example, the mean digestibility of the total organic matter in S. mossambicus feeding on detritus, plants and animal were 36.85, 33.5 and 29.5 respectively, and compared well with observations from elsewhere. It is hypothesised that the favourable nutrient quality of the available dietary material in the reservoirs of Sri Lanka, which could be and is effectively utilized by S. mossambicus, may have been, at least partially, responsible for its almost unprecedented success in Sri Lanka.  相似文献   

20.
Habitat size, habitat isolation and habitat quality are regarded as the main determinants of butterfly occurrence in fragmented landscapes. To analyze the relationship between the occurrence of the butterfly Cupido minimus and these factors, patch occupancy of the immature stages in patches of its host plant Anthyllis vulneraria was studied in the nature reserve Hohe Wann in Bavaria (Germany). In 2001 and 2002, 82 A. vulneraria patches were surveyed for the presence of C. minimus larvae. The occurrence was largely affected by the size of the food plant patches. In a habitat model that uses multiple logistic regression, the type of management and habitat connectivity are further determinants of species distribution. Internal and temporal validation demonstrate the stability and robustness of the developed habitat models. Additionally, it was proved that the colonization rate of C. minimus was significantly influenced by the distance to the next occupied Anthyllis patch. Concerning long-term survival of (meta-) populations in fragmented landscapes, the results show that lower habitat quality may be compensated by higher connectivity between host plant patches. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

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