نتایج جستجو برای: 40 n and long 44
تعداد نتایج: 17097299 فیلتر نتایج به سال:
a simple, sensitive and selective method for solvent extraction and spectrophotemetric determination of lanthanum (ii) europium (iii), and cerium (iii) is described , the rare earth metals are extracted into chloroform solution of n-phenylbenzohydroxamic acid (pbha) at ph 9-10 various parameters are studied to optimize the extraction conditions. the molar absorptivity is found to increase from ...
the concepts of similarity and dissimilarity have been the interest of many researchers. basically, in the studies the similarity between two objects or phenomena, has been discussed. in this thesis, we consider the case when the resemblance or similarity among three objects or phenomena of a set, 3-similarity in our terminology, is desired. later we will extend our definitions and propos...
BACKGROUND Dilatation of the pulmonary autograft is a major concern after root replacement for the Ross operation. The inclusion technique would avoid this drawback, but few data are available on the long-term results of this technique. We retrospectively analyze long-term results of both techniques. METHODS Of 218 patients undergoing the Ross operation between 1991 and 2006, 148 (68%) had ro...
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
we describe here a suitable approach for the synthesis of n-unsubstituted monocyclic b-lactams under mild reaction conditions by the annelation of imines with substituted acetylchlorides. in this method the reaily available phtalimidoacetyl chloride were allowed to react with - dibenzylideneiminotoluene (hydrobenzamide) in the presence of an equimolar amount of triethylamine in refluxing toluen...
BACKGROUND The multicomponent serogroup B meningococcal (4CMenB) vaccine was recently licensed for use in Europe. There are currently no data on the persistence of bactericidal antibodies induced by use of this vaccine in infants. Our objective was to evaluate serogroup B-specific bactericidal antibodies in children aged 40-44 months previously vaccinated at 2, 4, 6 and 12 months of age. METH...
ABSTRACT The fragile X syndrome is the most frequent cause of inherited mental retardation. The fragile site is on the long arm of X chromosome in X q27.3 region. Incidence of syndrome is 1 in 2000 in males and 1 in 2500 in females. This fragile site is visible only with using of special cultural technices. Since females have two X chromosomes, this signs apear less than males. The females who...
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