Urea is the most commonly used nitrogen fertilizer worldwide. The overused urea in agricultural fields may affect the soil organisms especially, the earthworms which are known well for their role in soil fertility. Earthworms are typically inferred as soil indicators without which soil fertility cannot be measured directly. An acute toxicity test of urea to earthworm (Eisenia fetida) was perfor...

Background: Nitrogen is the most important nutrient requirement for plants. Nitrogen supplying affected the leaf area, carbon fixation, glandular trichomes formation, ATP and NADPH content which resulted to the terpenoids biosynthesis enhancement and essential oils accumulation. Objective: This study was aimed to evaluate changes of essential oil content and components by use different levels ...

In order to elucidate aspects of the mechanism of the hydrolytic enzyme urease, theoretical calculations were undertaken on a model of the active site, using density functional theory. The bridging oxygen donor that has been found in the crystal structures was determined to be a hydroxide ion. The initial coordination of urea at the active site occurs most likely through the urea oxygen to the ...

BACKGROUND AND OBJECTIVES Vaptans (vasopressin V(2)-receptor antagonists) are a new approach for the treatment of hyponatremia. However, their indications remain to be determined, and their benefit compared with that of the usual treatments for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) have not been evaluated. This prospective, long-term study compared the efficacy, t...

ABSTRACT- Crop residue is applied to amend soil properties and increase crop yield. In this study, the effects of rapeseed residues and different rates of nitrogen on grain yield and yield components of sunflower and weed dry matter were investigated. The experiment was conducted at the Experimental Farm of College of Agriculture, Shiraz University, located at Badjgah, Shiraz, Iran in 2007-2008...

In cirrhotic patients without renal failure, salt retention could result from a decreased effective intravascular volume or could be a primary event leading to increased intravascular volume. Clearance of urea and uric acid depend on an effective intravascular volume. In the syndrome of inappropriate secretion of antidiuretic hormone (SIADH)--a state of increased intravascular volume--uric acid...

Background: The current research is designed to investigate alterations in lipid peroxidation (malondialdehyde - MDA) and renal markers (urea creatinine) patients of chronic failure (CRF) as compared the control group. Method: study included 55 subjects, who were separated into two groups: group, which 15 healthy members with no history systematic illness; 40 CRF divided four groups “Non: witho...

soil enzyme activities can be used as indicators of soil quality for assessing the sustainability of agricultural ecosystems. the objective of this study was to determine the effects of barley residue input rate, burning, urea fertilizer and tillage management on activities of alkaline phosphatase and urease under field conditions, after a period of 90 days. the experiment was carried out based...

Urea is the major nitrogen (N) form supplied as fertilizer in agriculture, but it is also an important N metabolite in plants. Urea transport and assimilation were investigated in Arabidopsis (Arabidopsis thaliana). Uptake studies using (15)N-labeled urea demonstrated the capacity of Arabidopsis to absorb urea and that the urea uptake was regulated by the initial N status of the plants. Urea up...

The inherent skeletal and thermal features to forge polymers by step-growth polymerization are conflicting with any depolymerization strategies via cascade back-biting reactions that necessitate adequate ceiling temperature, spacers, functionalities create cyclic compounds. Here, we report the edition of poly(carbonate-urea)s poly(carbonate-amide)s depolymerized on demand into their native prec...