نتایج جستجو برای: pb 2

تعداد نتایج: 2553392  

2011
Ezzatollah Najafi Mostafa M. Amini Seik Weng Ng

In the centrosymmetric dinuclear title compound, [Pb(2)(C(10)H(6)NO(2))(2)(CH(3)COO)(2)(C(2)H(5)OH)(2)], one O atom of the carboxyl-ate group of the quinoline-2-carboxyl-ate anion connects the two Pb(II) atoms. The Pb(II) atom is surrounded by four O atoms and one N atom in a Ψ-octa-hedral PbO(4)NE geometry (E is the electron lone pair). Two longer Pb⋯O inter-actions distort the geometry toward...

1997

To study the specific target to which phenobarbital (PB) binds, resulting in the induction of cytochrome P450, we prepared two azido-PBs (AZPBs) as photoaffinity ligands. The azido substituent was introduced at the paraor meta-position of the PB aromatic ring. In this study, we estimated the utility of these compounds by examining their inducing activities in vivo in rats. Induction was assesse...

2011
Ezzatollah Najafi Mostafa M. Amini Seik Weng Ng

The four cupferronate ions in the dinuclear title compound, [Pb(2)(C(6)H(5)N(2)O(2))(4)], O,O'-chelate to the two Pb(II) atoms; two of the four nitroso O atoms are also involved in bridging. The geometry of both five-coordinate Pb(II)atoms is distorted Ψ-octa-hedral; if another two longer inter-molecular Pb⋯O inter-actions [at 2.955 (1) and 3.099 (1) Å] are considered, the geometry is a distort...

2007
Xiao-Peng Xuan Pei-Zheng Zhao Shu-Xia Zhang

In the centrosymmetric binuclear title complex, [Pb(2)(C(7)H(5)O(3))(4)(C(12)H(8)N(2))(2)(H(2)O)(2)]·H(2)O, each Pb atom is eight-coordinated in a PbO(6)N(2) environment by two N atoms from the 1,10-phenanthroline (phen) ligand, five carboxylate O atoms from four 3-hydroxy-benzoate anions and one O atom from the coordinated water mol-ecule in a distorted bicapped trigonal-prismatic geometry. Th...

2013
Ahmed Belatik Surat Hotchandani Robert Carpentier

The action of the environmental toxic Pb(2+) on photosynthetic electron transport was studied in thylakoid membranes isolated from spinach leaves. Fluorescence and thermoluminescence techniques were performed in order to determine the mode of Pb(2+) action in photosystem II (PSII). The invariance of fluorescence characteristics of chlorophyll a (Chl a) and magnesium tetraphenylporphyrin (MgTPP)...

Journal: :The Journal of pharmacology and experimental therapeutics 2006
Sonia Mesia-Vela Rosa I Sanchez Kenneth R Reuhl Allan H Conney Frederick C Kauffman

Exposure of female August-Copenhagen Irish (ACI) rats for 28 weeks to 3 mg of estradiol (E(2)) contained in cholesterol pellets elevated blood E(2) levels and caused palpable mammary tumors in all animals. Coadministration of phenobarbital (PB) in their drinking water reduced the incidence, number, and size of mammary tumors (MTs) but did not reduce blood E(2) levels. Inhibition of MTs by PB wa...

Journal: :The Science of the total environment 2014
N Walraven B J H van Os G Th Klaver J J Middelburg G R Davies

Lake sediments provide a record of atmospheric Pb deposition and changes in Pb isotope composition. To our knowledge, such an approach has not previously been performed in The Netherlands or linked to national air monitoring data. Results are presented for Pb content and isotope composition of (137)Cs dated lake sediments from 2 Dutch urban lakes. Between 1942 and 2002A.D. anthropogenic atmosph...

Journal: :Aquatic toxicology 2008
Oana Birceanu M Jasim Chowdhury Patricia L Gillis James C McGeer Chris M Wood Michael P Wilkie

Models such as the Biotic Ligand Model (BLM) predict how natural organic matter (NOM) and competing ions (e.g., Ca(2+), H(+) and Na(+)) affect metal bioavailability and toxicity in aquatic organisms. However, such models focus upon individual metals, not metal mixtures. This study determined whether Pb and Cd interact at the gill of rainbow trout (Oncorhynchus mykiss) when trout were exposed to...

2012
Gholam Hossein Shahverdizadeh Seik Weng Ng Edward R. T. Tiekink Babak Mirtamizdoust

In the title Pb(II) complex, [Pb(2)(C(2)Cl(3)O(2))(2)(NO(3))(2)(C(12)H(8)N(2))(2)](n), the 1,10-phenanthroline ligand is chelating, the nitrate anion chelates one Pb(II) ion and simultaneously bridges a neighbouring Pb(II) ion via the third O atom, and the trichloro-acetate anion is bidentate, bridging two Pb(II) ions. The coordination geometry is based on a penta-gonal-bipramidal geometry defi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان زنجان - دانشکده علوم پایه 1389

دو پلیمر کویوردیناسیونی سرب(ii) جدید از مالئیک اسید و فوماریک اسید، [pb(µ7-mal)]n (1) و [pb(µ6-fum)]n (2) از طریق روش سونوشیمی سنتز و با میکروسکوپ الکترونی روبشی، پراش اشعه x و طیف سنجی ir شناسایی شده اند. رفتار گرمایی نمونه های نانو و توده ترکیبات 1 و 2 مطالعه و با یکدیگر مقایسه شدند. ترکیب 1 به وسیله بلورنگاری اشعه x از نظر ساختاری شناسایی شد. اثر حلال بر روی اندازه و ریخت شناسی نانوساختار تر...

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