recently, 6-(2-naphthyl)-2, 3-dihydro-as-triazine-3-thione (ndtt) was synthesized in laboratory and used successfully for the spectrophotometric determination of nanogram levels of cu2+ in aqueous solution. this reagent forms a specific red complex with cu2+ ions after the extraction by chloroform at alkaline ph. the absorption of the complex in the uv region (313 nm) is about 8 times as strong...

Seeds of lettuce (Lactuca sativa L. cv. Grand Rapids) were imbibed and given either short irradiation with red or far red light prior to drying or dried under continuous red or far red light. Seeds treated with either short or continuous red germinate in darkness, whereas seeds treated with either short or continuous far red require a short exposure to red light, after a period of imbibition, t...

The infectious hepatitis B virus represents 42 nm spherical double-shelled particles. However, analysis of blood from hepatitis B virus carriers revealed the presence of smaller 22 nm particles consisting of a viral envelope surface protein. These particles are highly immunogenic and have been used in the design of hepatitis B virus vaccine produced in yeast. Upon expression in yeast, these pro...

Background: The cephalosporins class is among the most widely used group of antimicrobials worldwide. Antibiotics, together with other drugs and personal care products, make up a emerging contaminants. effects exposure to this chemical contaminants on non-target organisms are not well understood, as they still poorly studied. Therefore, study evaluated phytotoxicity five in Lactuca sativa. Meth...

Phytotoxicity of Daphne gnidium L. was evaluated through the effect of incorporating leaves, stems and roots biomass into soil (at 12.5, 25, 50g/Kg) and irrigation by their aqueous extracts (50g/L), on the growth of two crops (Lactuca sativa L. and Raphanus sativus L.) and two weeds (Peaganum harmala L. and Scolymus maculatus L.). Results revealed a perceptible phytotoxic effect which increased...

The combination of ethylene with CO(2) will completely overcome the thermodormancy of lettuce (Lactuca sativa L.) seeds at 35 C. This combination is effective if it is added to seeds either at the start or after several days of imbibition. The action of ethylene is dependent upon the CO(2) level present in the atmosphere surrounding the seeds. When CO(2) is trapped by KOH the ethylene effect is...

Vegetable transplanting is an important and advantageous practice in vegetables production systems. In recent years, the development of vegetable tools has increased, as well interest for automatic robotic transplanters. However, at present, feeding machines often still performed by hand. This paper presents design, testing a needle gripper two-finger transplanting. Both grippers were self-desi...

Contamination of plants and waters with nitrate and sodium is an important environmental problem that can affects humans. An experiment was carried out aiming to evaluate the effect of fertilization and irrigation water quality on NO3- and Na+ contents of drained water and lettuce (Lactuca sativa L.) plants in Rio Claro, São Paulo State, Brazil. Treatments were distributed in a factorial arrang...

Ethylene or thiourea can substitute for gibberellic acid but not for red light in breaking the secondary dormancy induced by extended dark storage of fully hydrated lettuce seeds (Lactuca sativa cv. Grand Rapids). After 10 days of storage, ethylene, thiourea, or gibberellic acid applied either separately or in any combination in conjunction with red light induced near maximal germination. When ...