نتایج جستجو برای: s i l i c a
تعداد نتایج: 14200971 فیلتر نتایج به سال:
a simple and mild procedure for the conversion of anilines into aryl isocyanates is described using the 3-hydroxypropylammonium acetate (hpaa) ionic liquid as a novel and efficient media has been explored in the synthesis of aryl isocyanates from the reaction of substituted urea with sodium nitrite in a water immiscible solvent. this ionic liquid can be easily recovered and reused for many time...
our aim in this work is the synthesis and study optical and structural properties of gold nanoparticles.gold (iii) chloride trihydratewas taken as metal precursor, ascorbic acid at the presence of an appropriate amount of naoh as reducing agent and polyvinylpyrrolidonek-30 (pvp k-30) as a stabilizing and capping agent. the reaction was performed in high-speed stirring rate at room temperature.s...
primary antibody deficiencies are the most frequent primary immunodeficiency disorders. bronchiectasis as a feature of these disorders may be developed due to some factors such α-1-antitrypsin deficiency. in order to determine the prevalence of two common α-1-antitrypsin deficiency alleles (pi*z and pi*s) in iranian patients with antibody deficiency, this study was performed. the prevalence of ...
background: mycobacterium tuberculosis lipid antigens take part in pathogenicity of the bacterium but the response of monocytes/macrophages to these antigens in tubercu-losis is not well known. objective: the aim of current investigation was to study the m. tuberculosis lipid antigens in tuberculosis pathogenesis. methods: in the present study m. tuberculosis lipid antigens were extracted. mono...
the chemical composition of the essential oil of fruits of pimpinella haussknechtiiboiss.was studied by gc-ms. after gc-ms analysis, one unknown component (56.7%) was observed, which was not characterized in the gc-ms library. the essential oil of p.hauskenekhtii was injected to hplc using ymc-pak-sil column (250 × 20 mm) with gradient system of hexane (a), and hexane: ethyl acetate, 9:1 (b) to...
in this study, the effect of drought and different concentrations of silicon was examined on seed yield, essential oil percentage and physio-chemicals properties in fennel plant. the experimental design was a split plot with three irrigation regimes: irrigation at 100, 70 and 40 percent of fc comprising the main treatments, and five levels of silicon foliar sprays (0, 2.5, 5, 7.5 and 10 mm) as ...
در سال 1951 آر. آرنز دو ضرب روی a" تعریف نمود که به ضرب آرنز چپ و ضرب آرنز راست موسوم اند. تحت هر یک از این دو ضریب a" تبدیل به یک جبر باناخ می شود. اگر این دو ضریب روی a" بر هم منطبق باشند جبر a را منظم آرنز می گوئیم. یک مسئله مهم و طبیعی بررسی ساختارهای جدیدی از جبرهای منظم آرنز است . بدیهی است که یک زیر جبر بسته از یک جبر منظم آرنز، منظم آرنز و جبرهای خارج قسمتی از یک جبر منظم آرنز نیز منظم ...
background: systemic lupus erythematosus (sle) is a chronic autoimmune disease which is characterized by b-cell abnormality and auto-antibody generation. since bacterial infections are the most important causes of mortality in these patients, pneumococcal vaccination is recommended for children with sle. objective: to investigate humoral immunity and specific-antibody formation in response to a...
abstract background and aims: multiple sclerosis (ms) is defined by the presence of inflammatory demyelinating plaques in the central nervous system (cns). it has been indicated that human herpes virus 6 (hhv-6) may play role in pathogenesis of ms. the aim of this study was to determine the presence of hhv-6 dna and anti hhv-6 igg in ms patients and controls. materials and methods: blood sample...
background: in order to diagnose the site of thrombi, radiolabeled streptokinase can be prepared. the radiolabeled compound can be used in imaging of thrombi in many cardiovascular diseases. materials and methods: streptokinase was successively labeled with [67ga]-gallium chloride using cyclic dtpa-dianhydride. the conjugation with dtpa was optimized for concentration, time and temperature foll...
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