The title urea derivative crystallizes as a monohydrate, C19H27N3O2·H2O. The central C3N grouping is almost planar (r.m.s. deviation = 0.0092 Å), and the amide and pyridine groups are ...substantially twisted out this plane dihedral angles = 62.80 (12) and 34.98 (10)°, respectively. Supramolecular double chains propagating along the b-axis direction feature in the crystal packing whereby linear chains sustained by N—H...O hydrogen bonds formed between the amide groups are linked by helical chains of water molecules (linked by O—H...O hydrogen bonds). The H atom that participates in these water chains is disordered over two positions of equal occupancy. The double chains are connected into a two-dimensional array by C—H...O contacts and the layers stack along the a axis.
The molecule of the title compound, C18H19N3O5, adopts a curved arrangement with the terminal benzene rings lying to the same side. The hydroxylbenzene ring is close to coplanar with the adjacent ...hydrazine residue dihedral angle = 11.14 (12)°, an observation which correlates with the presence of an intramolecular O—H...N hydrogen bond. The benzyl ring forms a dihedral angle of 50.84 (13)° with the adjacent carbamate group. A twist in the molecule, at the chiral C atom, is reflected in the dihedral angle of 80.21 (12)° formed between the amide residues. In the crystal, two-dimensional arrays in the ac plane are mediated by O—H...O and N—H...O hydrogen bonds.
The crystal structures of four (E)-meth-oxy-benzaldehyde oxime derivatives, namely (2-meth-oxy-benzaldehyde oxime, 1, 2,3-di-meth-oxy-benzaldehyde oxime, 2, 4-di-meth-oxy-benzaldehyde oxime, 3, and ...2,5-di-meth-oxy-benzaldehyde oxime, 4, are discussed. The arrangements of the 2-meth-oxy group and the H atom of the oxime unit are s-cis in compounds 1-3, but in both independent mol-ecules of compound 4, the arrangements are s-trans. There is also a difference in the conformation of the two mol-ecules in 4, involving the orientations of the 2- and 5-meth-oxy groups. The primary inter-molecular O-H(oxime)⋯O(hy-droxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O-H(oxime)⋯O(hy-droxy) hydrogen bonds generate symmetric R 2 2(6) dimers. A more complex dimer is generated in 4 from the O-H(oxime)⋯O(hy-droxy) and C-H(2-meth-oxy)⋯O(hy-droxy) hydrogen bonds. In all cases, further inter-actions, C-H⋯O and C-H⋯π or π-π, generate three-dimensional arrays. Hirshfeld surface and fingerprint analyses are discussed.
Résumé
L’objectif de l’étude était d’évaluer les performances des tests ImmunoComb® Toxo IgG et ImmunoComb® Toxo IgM pour le diagnostic biologique de la toxoplasmose chez les femmes enceintes à ...Cotonou. 266 femmes venues à l’hôpital avec une demande de sérologie toxoplasmique ont rempli un questionnaire et ont bénéficié d’un prélèvement pour le dosage des IgG et IgM anti
T. gondii
par le test rapide ImmunoComb® Toxo IgG, ImmunoComb® toxo IgM et par la méthode CIMA de l’automate Architect, considérée comme technique de référence. La sensibilité, la spécificité, les valeurs prédictives positives (VPP) et négatives (VPN) ont été calculées en vue de déterminer les performances du test rapide. La prévalence de la toxoplasmose par la technique de référence et le test rapide étaient respectivement de 48,9 % et 48,5 %. Cette prévalence était plus élevée chez les femmes plus âgées. Les performances du test Immuno-Comb® Toxo IgG étaient les suivantes : sensibilité = 97 %, spécificité=100 %, VPP =100 %, VPN = 97,1 %. Pour le test ImmunoComb® toxo IgM, les performances étaient : Sensibilité = 33,3 %, Spécificité =100 %, VPP = 100 %, VPN = 99,2 %. La séroprévalence obtenue montre qu’environ la moitié de la population de l’étude n’est pas immunisée visà-vis de la toxoplasmose et nécessiterait un suivi sérologique régulier jusqu’à l’accouchement. Avec les résultats ainsi obtenus, et étant donné les besoins du diagnostic biologique dans un contexte de proportion non négligeable du nombre de femmes non immunisées, ce test pourrait être préconisé dans le diagnostic biologique de la toxoplasmose à des niveaux périphériques de la pyramide sanitaire surtout pour la détection des IgG. Par contre pour les IgM, une autre politique de dépistage devrait être associée.
High-performance liquid chromatography (HPLC) coupled to an ICP-MS with an octapole reaction system (ORS) has been used to carry out quantitative speciation of selenium (Se) and arsenic (As) in the ...stream waters of a refining process. The argon dimers interfering with the ⁷⁸Se and ⁸⁰Se isotopes were suppressed by pressurizing the octapole chamber with 3.1 mL min⁻¹ H₂ and 0.5 mL min⁻¹ He. Four arsenic species arsenite—As(III), arsenate (As(V)), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)—and three inorganic Se species—selenite Se(IV), selenate Se(VI), and selenocyanate (SeCN⁻)—were separated in a single run by ion chromatography (IC) using gradient elution with 100 mmol L⁻¹ NH₄NO₃, pH 8.5, adjusted by addition of NH₃, as eluent. Repeatabilities of peak position and of peak area evaluation were better than 1% and about 3%, respectively. Detection limits (as 3σ of the baseline noise) were 81, 56, and 75 ng L⁻¹ for Se(IV), Se(VI), and SeCN⁻, respectively, and 22, 19, 25, and 16 ng L⁻¹ for As(III), As(V), MMA, and DMA, respectively. Calibration curve R ² values ranged between 0.996 and 0.999 for the arsenic and selenium species. Column recovery for ion chromatography was calculated to be 97 ± 6% for combined arsenic species and 98 ± 3% for combined selenium species. Because certified reference materials for As and Se speciation studies are still not commercially available, in order to check accuracy and precision the method was applied to certified reference materials, BCR 714, BCR 1714, and BCR 715 and to two different refinery samples—inlet and outlet wastewater. The method was successfully used to study the quantitative speciation of selenium and arsenic in petroleum refinery wastewaters.
KASCADE-Grande is an air-shower observatory devoted for the detection of cosmic rays with energies in the interval of 10 super(14) - 10 super(18) eV, where the Grande array is responsible for the ...higher energy range. The experiment comprises different detection systems which allow precise measurements of the charged, electron and muon numbers of extensive air-showers (EAS). These data is employed not only to reconstruct the properties of the primary cosmic-ray particle but also to test hadronic interaction models at high energies. In this contribution, predictions of the muon content of EAS from QGSJET II-2, SIBYLL 2.1 and EPOS 1.99 are confronted with the experimental measurements performed with the KASCADE-Grande experiment in order to test the validity of these hadronic models commonly used in EAS simulations.
The organic molecule in the title dihydrate, C18H19N3O6·2H2O, adopts a twisted U-shape with the major twists evident about the chiral C atom the C—N—C—C torsion angle is ...−88.2 (4) ° and about the oxygen–benzyl bond C—O—C—C = 74.2 (4) °. The conformation about the imine bond 1.290 (4) Å is E and an intramolecular O—H...N hydrogen bond helps to establish the near coplanarity of the hydroxybenzene and hydrazine groups. The crystal packing features O—H...O and N—H...O hydrogen bonds, leading to two-dimensional supramolecular arrays in the ab plane with weak C—H...π connections between the arrays.
•The effective muon attenuation and absorption lengths of air showers are investigated.•Air shower data of the KASCADE-Grande observatory is analyzed.•Predictions of the models SIBYLL 2.1, EPOS-LHC, ...QGSJET-II-02 and -04 are tested.•The studied models fail to describe consistently the attenuation of the muon data.
The evolution of the muon content of very high energy air showers (EAS) in the atmosphere is investigated with data of the KASCADE-Grande observatory. For this purpose, the muon attenuation length in the atmosphere is obtained to Λμ=1256±85−232+229(syst)g/cm2 from the experimental data for shower energies between 1016.3 and 1017.0 eV. Comparison of this quantity with predictions of the high-energy hadronic interaction models QGSJET-II-02, SIBYLL 2.1, QGSJET-II-04 and EPOS-LHC reveals that the attenuation of the muon content of measured EAS in the atmosphere is lower than predicted. Deviations are, however, less significant with the post-LHC models. The presence of such deviations seems to be related to a difference between the simulated and the measured zenith angle evolutions of the lateral muon density distributions of EAS, which also causes a discrepancy between the measured absorption lengths of the density of shower muons and the predicted ones at large distances from the EAS core. The studied deficiencies show that all four considered hadronic interaction models fail to describe consistently the zenith angle evolution of the muon content of EAS in the aforesaid energy regime.
The crystal structures of three salicyaldoxime compounds, namely 2-hy-droxy-4-methyl-benzaldehyde oxime, C
H
NO
,
, 2,4-di-hydroxy-benzaldehyde oxime, C
H
NO
,
, and ...2-hy-droxy-4-meth-oxy-benzaldehyde oxime, C
H
NO
,
, are discussed. In each compound, the hydroxyl groups are essentially coplanar with their attached phenyl group. The inter-planar angles between the C=N-O moieties of the oxime unit and their attached phenyl rings are 0.08 (9), 1.08 (15) and 6.65 (15)° in
,
and
, respectively. In all three mol-ecules, the 2-hy-droxy group forms an intra-molecular O-H⋯N(oxime) hydrogen bond. In compound (
), inter-molecular O-H(oxime)⋯O(hydrox-yl) hydrogen bonds generate
(14) dimers, related by inversion centres. In compound
, inter-molecular O-H(oxime)⋯O(4-hy-droxy) hydrogen bonds generate
9 chains along the
-axis direction, while O-H(4-hydrox-yl)⋯O(2-hydrox-yl) inter-actions form zigzag
6 spiral chains along the c-axis direction, generated by a screw axis at 1,
, 1/4: the combination of the two chains provides a bimolecular sheet running parallel to the
axis, which lies between 0-1/2
and 1/2-1
. In compound
, similar
9 chains, along the
axis direction are generated by O-H(oxime)⋯O(4-meth-oxy) hydrogen bonds. Further weaker, C-H⋯π (in
), π-π (in
) and both C-H⋯π and π-π inter-actions (in
) further cement the three-dimensional structures. Hirshfeld surface and fingerprint analyses are discussed.
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