نتایج جستجو برای: element boron
تعداد نتایج: 221337 فیلتر نتایج به سال:
The effect of boron on heterocystous and nonheterocystous dinitrogen fixing Cyanobacteria was examined. The absence of boron in culture media inhibited growth and nitrogenase activity in Nodularia sp., Chlorogloeopsis sp., and Nostoc sp. cultures. Examinations of boron-deficient cultures showed changes in heterocyst morphology. However, cultures of nonheterocystous Cyanobacteria, Gloeothece sp....
The boron (Z = 5) element is unique. Boron-based (nano-)materials are equally unique. Accordingly, the present special issue is dedicated to crystalline boron-based (nano-)materials and gathers a series of nine review and research articles dealing with different boron-based compounds. Boranes, borohydrides, polyhedral boranes and carboranes, boronate anions/ligands, boron nitride (hexagonal str...
The aim of this study was to evaluate the effect of rosin upon fixing boron in Styrax tonkinensis (Piere) wood treated with mixtures of 3% boric acid and 1% rosin sizing agent. After treatment, wood samples were also analyzed by scanning electron microscope observation and energy-dispersive X-ray spectroscopy (SEM-EDX). The results showed that all boron-rosin formulations impregnated Styrax ton...
In contrast to the generally boron-poor terrestrial environment, the concentration of boron in the marine environment is relatively high (0.4 mM) and while there has been extensive interest in its use as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the relatively depth independent, and the generally non-nutrient-like concentration profile of this...
The element boron plays a role in medical and biological fluids [1] which is not yet well investigat ed. Further it is questionable if boron is needed as a trace element in the hum an food. But due to its toxicity, boron containing drugs are largely for bidden in this country [2], With the daily food, boron is incorporated in amounts which are esti mated to 1 through 40 mg per day [3], where...
Although the trace element boron has yet to be recognized as an essential nutrient for humans, recent data from animal and human studies suggest that boron may be important for mineral metabolism and membrane function. To investigate further the functional role of boron, brain electrophysiology and cognitive performance were assessed in response to dietary manipulation of boron (approximately 0...
In the present study, free vibration behaviors of of carbon nanotube (CNT) and boron nitride nanotube (BNNT) have been investigated via Eringen’s nonlocal continuum theory. Size effect has been considered via nonlocal continuum theory. Nanotubes have become popular in the world of science thanks to their characteristic properties. In this study, free vibrations of Boron Nitride Nanotube (BNNT) ...
The element boron is not renowned among biologists, short of a few specialists who know that it is an essential nutrient for plants and an element in boromycin—an antibiotic compound produced by Streptomyces. Yet, on the whole, molecular biologists and, in particular, those in drug development seem to have little use for carbon’s left-hand neighbour in the periodic table. This is about to chang...
BORON (B) is a micronutrient element that plants require in trace amounts.The concentration range in which plants exhibit neither deficiency nor toxicity symptoms is narrower for B than for any other nutrient element. Plants can experience both B deficiency and B toxicity in a single growing season (Reisenauer et al., 1973). In humid regions, rainfall can cause excessive leaching of B, and fert...
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