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341.
Detection of cell-affecting agents with a silicon biosensor   总被引:9,自引:0,他引:9  
Cellular metabolism is affected by many factors in a cell's environment. Given a sufficiently sensitive method for measuring cellular metabolic rates, it should be possible to detect a wide variety of chemical and physical stimuli. A biosensor has been constructed in which living cells are confined to a flow chamber in which a potentiometric sensor continually measures the rate of production of acidic metabolites. Exploratory studies demonstrate several applications of the device in basic science and technology.  相似文献   
342.
Serdar  Ümit  Gülser  Coşkun  Akyüz  Burak  Balta  Ayşegül  Çil  Yusuf  Yilmaz Figen  Fatma 《Erwerbs-Obstbau》2022,64(2):237-244

The goal of this study was to determine the usability of nitrogen solution for hazelnut sucker management. This study was carried out from 2015 to 2016?at two hazelnut orchards; one established with the shrub (ocak) system in Atakum district and the other established with the multi-stemmed system in the Carsamba district, both in Samsun province. For sucker management, 21% ammonium sulphate (AS) and 26% calcium ammonium nitrate (CAN) fertilizer solutions were used. Doses of 0, 10, 15 and 20% of solutions for both fertilizers were tested. In the study, hazelnut suckers were removed by knife in July 2015 and March 2016. Nitrogen solution applications were started in September 2015 when suckers reached 20–30?cm length. In 2016 four applications were made from April to August. Fifteen days after the applications, the wilting ratio (starting from the tip) and newly emerged suckers per bush were determined. Nitrate, pH, and EC analyses were made with soil samples collected at the beginning of the experiment and compared to those taken 15 days after each application. As a result, a 10% dose of 21% ammonium sulphate fertilizer gave the best results for hazelnut sucker management. Nitrogen solution application should be started 1 to 1.5 months after removal of suckers by cutting with a knife. Suckers should be removed when they reach 15–20?cm length and before they are lignified. For effective sucker management, nitrogen solution application should be applied at least three times in a year.

  相似文献   
343.
In order to determine the absolute configuration of naturally occurring alloxanthin, a HPLC analytical method for three stereoisomers 1a–c was established by using a chiral column. Two authentic samples, (3S,3′S)- and meso-stereoisomers 1b and 1c, were chemically synthesized according to the method previously developed for (3R,3′R)-alloxanthin (1a). Application of this method to various alloxanthin specimens of aquatic animals demonstrated that those isolated from shellfishes, tunicates, and crucian carp are identical with (3R,3′R)-stereoisomer 1a, and unexpectedly those from lake shrimp, catfish, biwa goby, and biwa trout are mixtures of three stereoisomers of 1a–c.  相似文献   
344.
尼日利亚稻田养鱼加灯光诱虫应用效果分析   总被引:2,自引:1,他引:1  
在尼日利亚科基州进行不同沟凼的稻田养鱼加灯光诱虫应用研究,其沟凼模式分围沟和十字沟,灯光以煤油灯代替电灯,鱼稻品种均为当地常见品种。结果表明,开挖占稻田面积10%~15%不同类型的鱼沟或鱼坑,其投入成本相同,鱼稻产量相近,均比单纯稻田收入增加3.5~4.5倍。示范成果还进一步验证了以往在尼日利亚进行的灯光诱虫试验结论,即在稻田养鱼中增加灯光诱虫,能够将有害昆虫变为鱼的全价饲料,减少稻田的病虫害,鱼、稻分别增产14%和9.5%,达到经济效益和生态效益双丰收。  相似文献   
345.
A method is described for the determination of inorganic tin in biological samples by hydride generation-atomic absorption spectrometry (HG-AAS). A sample is extracted with ethyl acetate after addition of HCl and NaCl. The concentrated extract is passed through a silica gel column. The column is washed with ethanol, water, and 0.2N HCl successively, and then inorganic tin is eluted with 2N HCl and measured by HG-AAS. Recoveries from fish muscle spiked with 0.1 micrograms/g Sn4+ are 78.9 +/- 4.2% (average +/- standard deviation, n = 5). The detection limit is 0.01 micrograms/g as Sn.  相似文献   
346.
Abstract

The changes in quality and quantity of phenolic substances in the decaying process of rice straw in a soil were compared under moist and flooded conditions for 200 days. The amounts of phenolic substances divided into fractions of humic acid and fulvic acid, ether- and butanol-extractable and organic solvent-unextractable fractions, then the amounts of individual phenolic acids were determined. The following results were obtained.

1) Alkali-extractable total phenolics as well as individual phenolic acids decreased more rapidly under moist, than under flooded, conditions as rice straw decayed in the soil. The phenolics present were mainly attributable to the straw, not to the soil.

2) The decrease in the level of total phenolics in the early stage of the decaying process was mainly due to the decrease in ether-extractable phenolic compounds in the fulvic acid fraction, and in the later stage, was mainly due to the decrease in butanol-extractable phenolics in the humic acid fraction.

3) The amounts of butanol-extractable phenolics and organic solvent-unextractable phenolics were larger in humic acid than in fulvic acid. On the other hand, a larger amount of organic solvent-extractable phenolics, especially ether-extractable phenolics, was present in fulvic acid.

4) The degradation patterns and pathways of individual phenolic acids in the decaying process of rice straw in soil were found to be the lame as those of decaying straw without soil which were reported previously.

5) The level of phenolic substances in the humic acid was not greatly changed during the decaying process, but the phenolic substances in fulvic acid rapidly increased for 30 days and then rapidly decreased to a constant level.  相似文献   
347.
Abstract

The carbon (C) budget of managed grassland in a cool-temperate region of Japan was estimated using a combination of eddy covariance and the biometric method for five years, to evaluate the effect of manure application. Chemical fertilizer was applied to the fertilizer (F) plot at a rate of 79 ± 20 kg N ha?1 yr?1. In the manure (M) plot, dairy cattle manure was applied at a rate of 10 Mg fresh matter ha?1 yr?1 (1923 ± 407 kg C ha?1 yr?1, 159 ± 68 kg N ha?1 yr?1). There was no significant difference in seasonal gross primary production (GPP) and harvest between the treatment plots, indicating that both fertilizer and manure can increase the biomass production. Annual net ecosystem production (NEP) and ecosystem respiration (RE) was significantly different between the treatment plots. The difference in RE, and between M and F plots approximates heterotrophic respiration of manure (RHm), which ranged from 0.9 to 1.3 Mg C ha?1 yr?1. Average annual RHm was 1.1 ± 0.4 Mg C ha?1 yr?1, and accounted for 56% of the total amount of applied manure C. The annual net biome production (NBP) in the M plot (from 0.0 to 1.5 Mg C ha?1 yr?1) was significantly higher than in the F plot (?1.4 to 0.5 Mg C ha?1 yr?1). The long-term effect of manure application combined with chemical fertilizer did not reduce grass production compared with chemical fertilizer only; however, manure application decreased the NEP throughout manure decomposition, and long-term manure application enhanced the NBP.  相似文献   
348.
Antioxidant activity and phenolic content of Oregon caneberries   总被引:6,自引:0,他引:6  
Five types of caneberries [evergreen blackberries (Rubus laciniatus), marionberries (Rubus ursinus), boysenberries (Rubus ursinus x idaeus), red raspberries (Rubus idaeus), and black raspberries (Rubus occidentalis)] were analyzed for antioxidant activity by measuring their oxygen radical absorbance capacity (ORAC). In addition, the berries were analyzed for total phenolics, anthocyanins, procyanidins, and ellagic acid content. All of the berries had high ORAC activity ranging from 24 to 77.2 micromol of Trolox equiv/g of fresh berries. Anthocyanin content ranged from 0.65 to 5.89 mg/g, and phenolics ranged from 4.95 to 9.8 mg/g. Black raspberries had the highest ORAC and anthocyanin and phenolic contents. Only red raspberries had detectable amounts of procyanidin oligomers (monomer, dimers, and trimers). All berries had high levels of ellagic acid (47-90 mg/g), but boysenberries had the highest level prior to hydrolysis. The results from this study indicate that these caneberries were high in antioxidant activity and were rich sources of anthocyanins and phenolics.  相似文献   
349.
【目的】研究库尔勒香梨上可能诱导粗皮果形成的胁迫因子。【方法】基于分析库尔勒香梨粗皮果形成的基础上,对生长期的库尔勒香梨枝条采用50%程度地摘叶、外源喷施250 mmol/L的H2O22种人为逆境处理,在成熟期统计处理枝条上粗皮果率,对不同处理的果实进行组织切片染色,检测生理指标。【结果】库尔勒香梨成熟期对照组的粗皮果比率为18.10%,H2O2喷施和摘叶处理的粗皮果率分别为51.93%、29.52%;3组果实中果皮中的木质素含量分别为3.4%、4.9%、3.9%,果肉中的木质素含量分别为1.5%、1.7%、2.0%,2个处理组均提高了库尔勒香梨的粗皮果率以及果实中的木质素含量。H2O2喷施后外果皮的丙二醛(MDA)和活性氧(H2O2和O-2)含量显著增加,分别为对照的1.7和2.9倍。与之相应,库尔勒香梨果皮可溶性糖、淀粉等渗透调节物质含量也显著增加,分别为对照的1....  相似文献   
350.
A total of 304Rhizoctonia solani isolates and 60 binucleateRhizoctonia-like fungi were recovered from stems and tubers of infected potato plants over a 2-yr period in northeast Turkey.R. solani isolates were identified to 11 anastomosis groups (AGs): AG-1 (0.66%), AG-2-1 (5.6%), AG-2-2 (0.99%), AG-3 (83.9%), AG-5 (4.6%), AG-6 (0.66%), AG-8 (1.32%), AG-9 (0.33%), AG-10 (1.32%), AG-12 (0.33%), and AG-13 (0.33%). In the greenhouse tests, most of the AG-3 isolates were significantly more virulent than isolates belonging to other AGs on potato cv. Batum. Isolates of other anastomosis groups differed in their virulence. Results indicated that AG-3 is an important pathogen on potatoes grown in the study area. Five of 22 commercial and local potato cultivars evaluated for their reaction toR. solani AG-3 isolates (TP-2) under greenhouse conditions were highly resistant; the remaining cultivars exhibited different levels of susceptibility to the pathogen isolate. http://www.phytoparasitica.org posting July 14, 2005.  相似文献   
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