共查询到20条相似文献，搜索用时 31 毫秒
1.
A 19-mo survey of enterovirus in the Llobregat river, located south of Barcelona was conducted. Total coliforms, fecal coliforms, and fecal streptococci counts, as well as several physico-chemical parameters were also measured at two sampling sites. The data show a very high level of fecal and chemical pollution caused by untreated wastewater effluents from several suburbs of Barcelona. 相似文献
2.
M Toyoda H Susuki Y Ito M Iwaida 《Journal of the Association of Official Analytical Chemists》1978,61(3):508-512
The 2,4-xylenol method was modified and a gas-liquid chromatographic (GLC) method was developed for nitrate and nitrite determinations in several foods. Either a flame ionization (FID) or an electron capture detector (ECD) can be used. Proteins and fats are removed from warm alkaline water with zinc sulfate and filtered. The filtrate is evaporated to dryness, redissolved in water, and reacted with 2,4-xylenol in the presence of sulfuric acid to form 6-nitro-2,4-xylenol. Interfering chlorides are precipitated with silver sulfate and the nitrosylenol is extracted with hexane, concentrated, and injected. Nitrite in the filtrate is distilled at pH 5, collected in alkaline solution, and dried. The residue is oxidized to nitrate with permanganate in the presence of sulfuric acid, and then chromatographed in the same manner as nitrate. Recoveries from several foods were 83--100% for nitrate and 80--100% for nitrite. The limit of sensitivity was 0.1 ppm for both residues. 相似文献
3.
The present review article is dealing with the potentiality of micronutrients in terms of seed priming treatment and its effect within the plant system is considered. Since last 3 to 4 decades various scientists are working with different planting methods and introduced several seed invigoration techniques, one of them is seed priming. Seed priming is basically a restricted hydration treatment with appropriate timing, in which seeds are treated with various types of organic and inorganic compounds. Whereas in this review, we have discussed the potential of different micronutrients in seed priming treatments for escalating crop growth, development and grain yield. Micronutrient priming has several beneficial effects in the morpho-physiological, biochemical and molecular aspects of the plants. In most cases, micronutrient application through seed treatment has astonishingly performed better than other application methods. Being an easy and cost effective method of micronutrient application, seed priming offer an attractive option for resource-poor farmers. 相似文献
4.
Forato LA Doriguetto AC Fischer H Mascarenhas YP Craievich AF Colnago LA 《Journal of agricultural and food chemistry》2004,52(8):2382-2385
The alpha zein, the maize storage prolamin, is a mixture of several homologous polypeptides that shows two bands in SDS-PAGE, called Z19 and Z22. The conformation studies carried out by several authors in this mixture are conflicting. To elucidate these inconsistencies, we analyzed the conformation of the Z19 fraction, extracted from BR451 maize variety by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and small-angle X-ray scattering. The infrared results show that Z19 has 46% of alpha helix and 22% of beta sheet. The fast N-H to N-D exchange measured by (1)H NMR spectroscopy showed that Z19 is not a compact structure. The scattering measurements indicated an extended structure with 12 by 130 A. With these data, we have modeled the Z19 structure as a hairpin, composed of helical, sheet, turns, and secondary structures, folded back on itself. 相似文献
5.
This study examined the 130 current full-text titles in the BioOne.1 and BioOne.2 collections to determine whether they are peer-reviewed, contain book reviews, and are supplied by document delivery vendors. We identified indexing coverage in 11 major databases in agriculture and life sciences: Aquatic Sciences and Fisheries Abstracts (ASFA), AGRICOLA, Biological Abstracts, BIOSIS Previews, CAB Abstracts, Current Contents, Environmental Sciences and Pollution Abstracts, GeoRef, Scopus, ISI Web of Science, and Zoological Record. We concluded that the majority of the titles in BioOne collections are refereed and scholarly, indexed in several of the major indexing and abstracting journals in the field of agriculture and life sciences, and available via several major document delivery vendors. We find both BioOne collections to be valuable, useful, cost-effective journal aggregations. 相似文献
6.
Tabaripour Raheleh Sheidai Masoud Talebi Seyed Mehdi Noormohammadi Zahra 《Genetic Resources and Crop Evolution》2021,68(5):2003-2017
Genetic Resources and Crop Evolution - Hymenocrater comprises of 11 species throught the world. The genus is an Irano-Turanian elements, which has several usages in traditional medicine. Northeast... 相似文献
7.
R G Nash 《Journal of the Association of Official Analytical Chemists》1990,73(3):438-442
Extraction of several nitrogen-containing pesticides from water on solid-phase C18 cartridges was rapid and accurate. One analyst can extract greater than 48 samples/day. Recovery efficiencies were 77, 95, 92, 90, and 99% with detection limits of 0.20, 0.05, 0.05, 0.20, and 0.10 micrograms/L for carbofuran, atrazine, simazine, alachlor, and, cyanazine, respectively. Extraction of the atrazine and simazine dealkylation products (deethylatrazine and deethylsimazine) was less efficient, e.g., 26 and 9%, respectively. Comparisons with 10 U.S. Geological Survey samples gave similar results. 相似文献
8.
The seeds of forbs, grass, and woody halophytes were collected from a cool moist temperate habitat of North America and subtropical maritime desert conditions of Karachi, Pakistan. Sodium, potassium, calcium, magnesium, and chloride concentrations as well as total ash content were determined. Ion concentrations of seeds are expressed both as relative values and on a dry weight basis. Plants were found to vary in the total ash content of seeds and the relative distribution of ions. In general, temperate forbs and grasses had lower ion content of seeds and several tropical shrub species had the highest ionic content. 相似文献
9.
研究结果表明，粮果油经菜菌生态立体种植比传统禾谷类单一平作种植能创造更好的生态环境，光能利用率、植株体积、叶面积系数、植株干重均有不同程度的增长，且经济效益倍增。 相似文献
10.
Distribution, conservation status, trends, actions and ethnobotanical notes of segetal species growing in South Italy are presented and discussed. For the most threatened segetal species details and suggestions for their conservation are reported. Research work was made directly in the field for collecting samples and in the laboratory for checking several herbarium samples. To the best of our knowledges, a summary table of all species occurring in the field, of the investigated environments, and their ecological focus areas, is provided for the first time. 相似文献
11.
Charles E. Kellogg 《Geoderma》1974,12(4):347-362
The progress in soil genesis, classification, and cartography is traced from their early backgrounds, through the IVth International Conference of Pedology held in Rome in 1924. The decision was made then to broaden the membership through a new International Society of Soil Science with congresses in different countries. The first of these was held in the United States in 1927.Dramatic progress had been made by Dokuchaev and his school and by several others. Both in the old Russian Empire, in the United States, and elsewhere, kinds of soil unlike those in Western Europe had to be understood and used.Soil surveys, and their application to farming, forestry, and engineering were greatly improved during the 1920's and 1930's.The congresses of the International Society of Soil Science were very helpful in 1930 and 1935. Because of World War II, these were interrupted until the 1950 Congress. Other congresses were held in 1954, 1956, 1960, 1964, and 1968.The Society also held several special conferences. In addition, many members of the Society took important parts in other conferences sponsored by individual governments, the United Nations, and related U.N. agencies, including many concerned with progress in the newly developing countries.Still many new challenges lie ahead. 相似文献
12.
West LG Meyer KA Balch BA Rossi FJ Schultz MR Haas GW 《Journal of agricultural and food chemistry》2004,52(4):916-926
The importance of dietary sulforaphane in helping maintain good health continues to gain support within the health-care community and awareness among U.S. consumers. In addition to the traditional avenue for obtaining sulforaphane, namely, the consumption of appropriate cruciferous vegetables, other consumer products containing added glucoraphanin, the natural precursor to sulforaphane, are now appearing in the United States. Crucifer seeds are a likely source for obtaining glucoraphanin, owing to a higher concentration of glucoraphanin and the relative ease of processing seeds as compared to vegetative parts. Seeds of several commonly consumed crucifers were analyzed not only for glucoraphanin but also for components that might have negative health implications, such as certain indole-containing glucosinolates and erucic acid-containing lipids. Glucoraphanin, 4-hydroxyglucobrassicin, other glucosinolates, and lipid erucic acid were quantified in seeds of 33 commercially available cultivars of broccoli, 4 cultivars each of kohlrabi, radish, cauliflower, Brussels sprouts, kale, and cabbage, and 2 cultivars of raab. 相似文献
13.
党的十六届五中全会提出要大力开展社会主义新农村建设,以农村沼气建设为核心的“一池三改”在新农村建设中发挥了重要作用。笔者通过对四川省农村沼气建设和新农村建设情况的调查分析,肯定了以沼气建设为纽带的“一池三改”在社会主义新农村建设中的推动作用,总结了四川省在结合新农村建设中推广沼气的成功经验,指出了当前沼气建设中存在的不足,并提出了相应的对策建议。 相似文献
14.
Background Tetracycline is a widely used antibiotic in animal production. Significant amounts of the substance reach the soil via feces,
urine and manure application. As tetracycline is a persistent compound with antibacterial activity, its presence in soil may
have undesired direct and indirect effects. These have been investigated so far focusing on effects on selected microbial
functions.
Objectives The aim of the present study was to obtain comprehensive information on potential effects of tetracycline on the soil microflora
under environmentally relevant conditions. The investigations included function and structure of the microbial biocoenosis
and the distribution of resistance genes.
Methods Pig manure rich in tetracycline resistance genes was applied to a sandy soil. This soil as well as an unamended soil were
additionally treated with several concentrations of tetracycline. The spiked soils were incubated in outdoor lysimeters for
several months. Substrate induced respiration, PLFAs, ten selected resistance genes, and the concentrations of tetracycline
were determined.
Results The test concentrations, though far exceeding environmental relevance, caused only small effects. An establishment of resistance
could not be detected. Applied resistance genes were not detectable at the end of the study even in the presence of added
tetracycline.
Conclusion Due to the high sorption capacity of the antibiotic, environmentally relevant concentrations of tetracycline do not seem to
cause undesired effects on the soil microflora. 相似文献
15.
16.
Yasmin W. F. Tham Kazuhiko Takeda Hiroshi Sakugawa 《Water, air, and soil pollution》2008,194(1-4):5-12
The correlation of particulate PAHs, sulfur dioxide, nitrogen dioxide and ozone were examined. The pollution scenario of particulate PAHs, sulfur dioxide, nitrogen dioxide and ozone is also briefly presented as supplementary information. Both sulfur dioxide and nitrogen dioxide were found to have significant positive correlations with total particulate PAHs as well as with most individual PAH species studied, suggesting they mostly share the same common emission source and transportation pattern. On the other hand, ozone was observed to selectively have a strong negative correlation with several PAH species, namely BgP, BaP, BaA, Pyr and Ace, probably due to the ozonolysis reaction of these species. 相似文献
17.
F T Noggle C R Clark T W Davenport S T Coker 《Journal of the Association of Official Analytical Chemists》1985,68(6):1213-1222
Amphetamine samples obtained from clandestine laboratories often contain other by-product amines. The most common of these are the alpha-benzylphenethylamine derivatives. This article reports the independent synthesis of reference samples of these amines, spectrophotometric and chromatographic methods for their identification, as well as acute toxicological studies. The utility of the analytical methods is demonstrated by the analysis of several amphetamine samples containing these alpha-benzylphenethylamines. 相似文献
18.
Nine stream sites in the Blackfoot River watershed in southeastern Idaho were sampled in September 2000 for water, surficial sediment, aquatic plants, aquatic invertebrates, and fish. Selenium was measured in these aquatic ecosystem components, and a hazard assessment was performed on the data. Water quality characteristics such as pH, hardness, and specific conductance were relatively uniform among the nine sites examined. Selenium was elevated in water, sediment, aquatic plants, aquatic invertebrates, and fish from several sites suggesting deposition in sediments and food web cycling through plants and invertebrates. Selenium was elevated to concentrations of concern in water at eight sites (>5 g/L), sediment at three sites (>2 g/g), aquatic plants at four sites (>4 g/g), aquatic invertebrates at five sites (>3 g/g), and fish at seven sites (>4 g/g in whole body). The hazard assessment of selenium in the aquatic environment suggested low hazard at Sheep Creek, moderate hazard at Trail Creek, upper Slug Creek, lower Slug Creek, and lower Blackfoot River, and high hazard at Angus Creek, upper East Mill Creek, lower East Mill Creek, and Dry Valley Creek. The results of this study are consistent with results of a previous investigation and indicate that selenium concentrations from the phosphate mining area of southeastern Idaho were sufficiently elevated in several ecosystem components to cause adverse effects to aquatic resources in the Blackfoot River watershed. 相似文献
19.
Small fruits such as berries have low energy contents, but high contents of vitamins, micronutrients, and dietary fibers and constitute a good source of natural antioxidant compounds that are important constituents of the human diet. This study identified a large number of compounds in an extract of black currant showing high antioxidant activity and compared their profile in various parts of the plants (leaves, buds, and berries). If it was known that berries contained very high levels of natural phenolic compounds, this study showed that leaves and buds could also be considered good sources of natural antioxidants. Indeed, they contained high amounts of phenolic acids, flavonoids, and carotenoids. An acetone mixture can extract several classes of phenolic compounds with a good yield of flavonols, flavan-3-ols, and anthocyanins. 相似文献
20.
Red soils in Greece are distributed throughout the country, but they occur more frequently in the southern provinces and constitute important soil resources supporting several land utilization types. They can be grouped into two categories: the autochthonous and the allochthonous. The former soils are found on hard limestone and on basic igneous rocks in sloping mountainous or hilly landscapes. Moreover, they can be found on mica schists and gneisses in locations adjacent to marble or calcareous mica schists.Allochthonous red soils are wide-spread on late Tertiary and Pleistocene surfaces in the lowlands. Many of these deep deposits have red strata, a few decimeters to several meters thick, or red-colored and fine-textured layers interbedded with light colored deposits of marl, or conglomerates and also with thick strata enriched with calcareous concretions. They are distributed in the thermo- and meso-mediterranean bioclimatic zones. These sites have a common feature, the gently sloping terrain that ensures efficient drainage.There are some differences in chemical and physical properties and in the clay mineralogy of the two groups of Greek red soils. Palygorskite is present in some soils developed on basic rocks; the clay minerals of the allochthonous soils on Pleistocene and late Pliocene seems to be mixed with micas in significant amounts.Soil forming factors required for the formation of red soils are: (a) parent material containing iron-bearing minerals, and rich in bases, (b) slope gradients and/or water permeabilities of the bed-rock securing excessive drainage and (c) vegetation cover that does not produce high amounts of, and deeply distributed organic matter.The allochthonous red soils have likely inherited their color from their parent materials that were transported from the originally formed residual soils on hard limestone. The soils retain the red color in the thermo-mediterranean zone only on sloping terrains. The soils on these landscapes are frequently stratified.The Greek red soils belong to the great groups of: Rhodoxeralfs, Palexeralfs, Xerochrepts, Orthents. Large portions of the allochthonous soils have been desertified or have been severely degraded and their extensive exploitation is not recommended.Soil management practices applied in the allochthonous soils include erosion control, preservation of organic matter, minimum tillage, split application of nitrogen using non-acidifying fertilizers, irrigation, soil water conservation and sheltered agriculture. 相似文献