Crystal structure of copper(II) bis-hexafluoroacetylacetonate

An X-ray diffraction investigation has performed for copper(II) bis-hexafluoroacetylacetonate (Bruker AXS P4 automatic diffractometer, MoK _{pg0g4286/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">} radiation, t = –25°C). Crystal data for C₁₀H₂CuF₁₂O₄: a = 5.530(1) Å, b = 6.038(1) Å, c = 11.266(2) Å, pg0g4286/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0"> = 95.948(3)°, pg0g4286/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"> = 101.743(3)°, pg0g4286/xxlarge947.gif" alt="gamma" align="MIDDLE" BORDER="0"> = 92.298(3)°, space group; P1, V = 365.6(1) ų, Z = 1, d _calc = 2.169 g/cm³. The square-planar environment of the copper atom (Cu-O_av 1.912 Å, pg0g4286/xxlarge8736.gif" alt="ang" align="BASELINE" BORDER="0">O-Cu-O_av 93°) is completed to bipyramidal by two fluorine atoms of the neighboring molecules, Cu...F 2.71 Å and 2.75 Å.Original Russian Text Copyright © 2004 by S. A. Gromilov, I. A. Baidina, P. A. Stabnikov, and G. V. RomanenkoTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 502–507, May–June 2004.     

Calculation of Families of Stationary Filtration Convection Regimes in a Narrow Container

A plane Darcy filtration convection problem for rectangular containers elongated in the vertical direction is considered. By the spectralpg34625r94l45381/xxlarge8208.gif" alt="dash" align="MIDDLE" BORDER="0">difference method, which preserved cosymmetry of the initial problem, evolution of families of stationary regimes from the onset of instability on the primary family till the collision of the families is studied.     

Simultaneous determination of etonogestrel and ethinyl estradiol in human plasma by UPLC‐MS/MS and its pharmacokinetic study

A selective, sensitive and rapid ultra‐performance liquid chromatography tandem mass spectrometry method was developed and validated for the simultaneous determination of etonogestrel (ENG) and ethinyl estradiol (EE) in human plasma. The analytes and their deuterated internal standards, ENG‐d7 and EE‐d4, were extracted from plasma samples by solid‐phase extraction on HyperSep™ Retain PEP cartridges. The chromatographic analysis was performed on an Acquity UPLC HSS Cyano column, 100 Å (50 × 2.1 mm, 1.8 μm), column using gradient mobile phase, acetonitrile and 2.0 mm ammonium trifluoroacetate at 0–1.7 min (65:35, v/v) and 1.8–2.7 min (95:5, v/v) with 0.250 mL/min flow rate. Analytes and IS protonated precursor → product ion transitions (ENG, m/z 325.2 → 257.2; EE, m/z 530.2 → 171.2; ENG‐d7, m/z 332.2 → 263.2; EE‐d4, m/z 534.2 → 171.2) were monitored on a Triple Quadrupole Mass spectrometer (TQMS), operating in multiple reaction monitoring and positive ionization mode. The calibration curves were established at 10.00–2500 pg/mL for ENG and 1.500–150.0 pg/mL for EE with a correlation coefficient (r²) ≥0.9996 for both. The validated method was successfully applied to support a bioequivalence study of 0.15 mg ENG and EE 0.03 mg tablet formulation, administered in 24 healthy Indian females. Method reliability was assessed by reanalysis of 94 incurred study samples.     

A -algorithm for convex minimization

For convex minimization we introduce an algorithm based on pg592p7707566332/MediaObjects/s10107-005-0630-3flb2.gif" alt="MediaObjects/s10107-005-0630-3flb2.gif" align="middle">-space decomposition. The method uses a bundle subroutine to generate a sequence of approximate proximal points. When a primal-dual track leading to a solution and zero subgradient pair exists, these points approximate the primal track points and give the algorithm's pg592p7707566332/MediaObjects/s10107-005-0630-3flb3.gif" alt="MediaObjects/s10107-005-0630-3flb3.gif" align="middle">, or corrector, steps. The subroutine also approximates dual track points that are pg592p7707566332/MediaObjects/s10107-005-0630-3flb4.gif" alt="MediaObjects/s10107-005-0630-3flb4.gif" align="middle">-gradients needed for the method's pg592p7707566332/MediaObjects/s10107-005-0630-3flb4.gif" alt="MediaObjects/s10107-005-0630-3flb4.gif" align="middle">-Newton predictor steps. With the inclusion of a simple line search the resulting algorithm is proved to be globally convergent. The convergence is superlinear if the primal-dual track points and the objective's pg592p7707566332/MediaObjects/s10107-005-0630-3flb4.gif" alt="MediaObjects/s10107-005-0630-3flb4.gif" align="middle">-Hessian are approximated well enough. Dedicated to Terry Rockafellar who has had a great influence on our work via strong support for proximal points and for structural definitions that involve tangential convergence. On leave from INRIA Rocquencourt Research of the first author supported by the National Science Foundation under Grant No. DMS-0071459 and by CNPq (Brazil) under Grant No. 452966/2003-5. Research of the second author supported by FAPERJ (Brazil) under Grant No.E26/150.581/00 and by CNPq (Brazil) under Grant No. 383066/2004-2.     

Analysis of nitrosamines by GC2 with a photoionization detector

The use of a photoionization detector (PID) coupled to a glass capillary gas chromatography (GC²) separation system for the detection of carcinogenic nitrosamines was investigated. The components analyzed gave a linear response with a lower detection limit of 50 to 100 pg with the 10.2 eV ionization source. No detector response was obtained with an ionization energy of 9.5 eV. Chromatography of meat extracts indicated their complex molecular composition. Simple liquid chromatographic cleaning procedures significantly decreased the complexity of these samples, but not sufficiently for the accurate quantition of nitrosamine components.     

Separation of histamine and its metabolites using glass capillary gas chromatography and a nitrogen detector

Complete separation of the TMS derivatives of histamine, 1-methyl histamine and 3-methyl histamine was achieved in two minutes in a 7 m × 0.25 mm column coated with SP 2250. Using NPD, histamine was detectable at levels as low as 20 pg. This offers a rapid, sensitive procedure with potential for clinical diagnosis and food analysis.     

On the Weak Limiting Behavior of Almost Surely Convergent Row Sums from Infinite Arrays of Rowwise Independent Random Elements in Banach Spaces

For an array {V _nk ,kpg35484m0/xxlarge8805.gif" alt="ge" align="MIDDLE" BORDER="0">1,npg35484m0/xxlarge8805.gif" alt="ge" align="MIDDLE" BORDER="0">1} of rowwise independent random elements in a real separable Banach space pg35484m0/10959_2004_Article_484111_TeX2GIFIE1.gif" alt=" $$X$$ " align="middle" border="0"> with almost surely convergent row sums pg35484m0/10959_2004_Article_484111_TeX2GIFIE2.gif" alt=" $$S_n = \sum {_{k = 1}^\infty {\text{ }}V_{nk} ,n \geqslant 1} $$ " align="middle" border="0"> , we provide criteria for S _n –A _n to be stochastically bounded or for the weak law of large numbers pg35484m0/10959_2004_Article_484111_TeX2GIFIE3.gif" alt=" $$S_n - A_n \xrightarrow{P}0$$ " align="middle" border="0"> to hold where {A _n ,npg35484m0/xxlarge8805.gif" alt="ge" align="MIDDLE" BORDER="0">1} is a (nonrandom) sequence in pg35484m0/10959_2004_Article_484111_TeX2GIFIE4.gif" alt=" $$X$$ " align="middle" border="0"> .     

Freeze-Dried Complexes of Furosemide with β-Cyclodextrin Derivatives

A freeze-drying method was used to prepare complexes of furosemide (guest) with three derivatives of pg/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-cyclodextrin (hosts) in different molecular ratios in order to increase the aqueous solubility and rate of dissolution of the drug, and also to study the influence of this method on different parameters of the guest and the host, such as the diffusion rate constant and the partition coefficient, and additionally the surface tension activity of the host (if any). The hosts were found to have significant, increasing effects on the solubility and the rate of dissolution of furosemide. X-ray diffraction confirmed the host–guest interaction, in support of the earlier results. The freeze-drying method increased the diffusion rate of the drug in complex form, while the partition coefficient varied with the type of pg/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-cyclodextrin in the product. It is well known that CD derivatives are highly surface active which gives rise to their hemolytic action. Our observations showed that their presence with furosemide in complex form might decrease (if not diminish) the hemolytic action.     

基于全反射原理的X荧光分析技术及其应用研究

本文简单介绍了一种目前我国应用很少但很有竞争力的新兴元素分析方法——全反射Ｘ荧光（ＴＸＲＦ）分析技术,我们自行研制的分析装置的最低检测限,对于Ｃｕ靶、Ｍｏ靶达到ｐｇ级,其相对检测限达到ｎｇ／ｇ。作为应用范例,还叙述了一种海洋软体动物“牙齿”的定量分析,并给出了相应的Ｘ荧光谱图和分析结果。