Crystal Structure and Interaction of 6-Amino Coumarin with Nitrite Ion for Its Selective Fluorescence Detection

ABSTRACT

6-Amino coumarin has been established as an efficient nitrite ion selective fluorescent sensor. The developed method shows linearity up to 1.6 × 10^?6 mol L^?1 of nitrite ion concentration. Interference from other common anions is almost negligible. The reagent shows strong binding affinity towards nitrite ion as evident from its binding constant value (5.8 × 10⁴), estimated by Stern-Volmer method. Some real samples were analyzed. Single crystal X-ray structure of the reagent is reported. Preliminary computational studies on the molecular level interaction between the reagent and nitrite ion were performed by density functional theory (DFT, B3LYP) method.     

Feller Generators with Measure-valued Drifts

We construct a L ^p -strong Feller process associated with the formal differential operator ? Δ + σ ?? on \(\mathbb R^{d}\), \(d \geqslant 3\), with drift σ in a wide class of measures (e.g. the sum of a measure having density in weak L ^d space and a Kato class measure), by exploiting a quantitative dependence of the smoothness of the domain of an operator realization of ? Δ + σ ?? generating a holomorphic C ₀-semigroup on \(L^{p}(\mathbb R^{d})\), p > d ? 1, on the value of the relative bound of σ.     

Partie 1: La nouvelle enceinte destinée à Ia production de I'or colloidal radioactif 198 Au

Une nouvelle enceinte destinée à la production de l,or colloïdal radioactif¹⁹⁸Au à usage thérapeutique et diagnostique est construite dans le Laboratoire de Chimie de Haute Activité à l'Institut des Sciences Nucléaires ?Boris Kidri?”. L'enceinte comporte deux appareils pour la préparation des colloïdes de l'or radioactif, permettant une production permanente méme au cas où l'un des appareils est accidenté. C'est grâce à une conception originale de la protection en plomb que l'accès aus appareils et aux stocks des effluents est rendu facile et ainsi que les systèmes de commande des processus des processus chimiques et la manipulation dans l,enceinte sont bien simplifiés     

Hexachloroplatinates of the Lanthanides: Syntheses and Thermal Decomposition of [M(NO3)2(H2O)6]2[PtCl6]·2H2O (M = La,Pr) and [M(NO3)(H2O)7][PtCl6]·4H2O (M = Gd,Dy)

The reaction of the nitrates M(NO₃)₃·6H₂O (M = La, Pr) and (H₃O)₂PtCl₆ led to yellow single crystals of [M(NO₃)₂(H₂O)₆]₂[PtCl₆]·2H₂O (M = La, Pr) (monoclinic, P2₁/c, Z = 2, La/Pr: a = 697.4(3)/695.5(1), b = 1654.5(1)/1652.5(2), c = 1317.7(6)/1318.5(3) pm, β = 93.97°(7)/93.93°(2), R_all = 0.0169/0.0659) while the reaction of M(NO₃)₃·5H₂O (M = Gd, Dy) and (H₃O)₂PtCl₆ yielded yellow single crystals of [M(NO₃)(H₂O)₇][PtCl₆]·4H₂O (monoclinic, P2₁/n, Z = 4, Gd/Dy: a = 838.72(3)/838.40(2), b = 2131.98(6)/2139.50(7), c = 1142.63(3)/1143.10(3) pm, β = 95.670(4)/95.698(3), R_all = 0.0475/0.0337). The crystal structures consist of octahedral [PtCl₆]^2? anions and complex [M(NO₃)₂(H₂O)₆]₂⁺ and [M(NO₃)(H₂O)₇]²⁺ cations, respectively. The thermal decomposition of both types of compounds leads via various steps to elemental platinum and the oxide chlorides MOCl (M = La, Pr, Gd, Dy).     

Aspects of auditing in clinical laboratories

Quality and patient safety are terms that both providers and recipients of healthcare are very familiar with. Accreditation is another term that is closely linked to quality and patient safety. Audit is a systematic, independent, and documented process for obtaining evidence and evaluating it objectively to determine the extent to which audit criteria are fulfilled. Accreditation and audit are integral components of the same process. Three different types of audit are well recognized—internal, external, and co-operative. Reading of relevant documents, observation of laboratory practices, and asking open-ended probing questions are important auditing techniques. For auditing to be successful, experienced, qualified, and well trained auditors are essential. Furthermore, the auditor should be open-minded, not prejudiced, a team player and effective communicator, both in writing and verbally. In many instances, the emphasis for seeking laboratory accreditation has shifted from building quality systems—to produce reliable results and ensure patient safety—to just passing the inspection. Recently, the emphasis for laboratory quality improvement has been placed on pre and post-analytical processes in preference to analytical quality. The analytical quality of laboratory results is still far from ideal and it may be detrimental if less emphasis is placed on this aspect of laboratory medicine. Auditing or on-site inspection as a regulatory tool does not work or present a realistic picture of laboratory quality. A continuous quality improvement approach will help laboratories to build quality into their systems. Presented at the Conference “Excellence in Laboratory Medicine”, November 2007, Al Ain, United Arab Emirates.     

Linear regression model of DNA sequences and its application

We constructed six new models to analyze the DNA sequences. First, we regarded a DNA primary sequence as a random process in t and gave three ways to define nucleotides' random distribution functions. We extracted some parameters from the linear model and analyzed the changes of the nucleotides' distributions. In order to facilitate the comparison of DNA sequences, we proposed two ways to measure their similarities. Finally, we compared the six models by analyzing the similarities of the DNA primary sequences presented in Table 1 and selected the optimal one.     

Complexes of N‐Thiophosphorylthiourea α‐NaphthylNHC(S)NHP(S)(OiPr)2 (HL) with Copper(I). Crystal Structures of HL and Cu(PPh3)2L

Reaction of the potassium salt of N‐thiophosphorylated thiourea α‐naphthylNHC(S)NHP(S)(OiPr)₂ ( HL ) with Cu(PPh₃)₃I in aqueous EtOH/CH₂Cl₂ leads to the mononuclear complex [Cu(PPh₃)₂L–S,S′]. By using copper(I) iodide instead ofCu(PPh₃)₃I, the polynuclear complex [Cu_n(L–S,S′)_n] was obtained. The structures of these compounds were investigated by elemental analysis, ¹H and ³¹P{¹H} NMR and IR spectroscopy. The crystal structures of HL and Cu(PPh₃)₂L were determined by single‐crystal X‐ray diffraction.