18FFDGPETCT inside radiation therapyinduced parotid glandular inflammation

Two polymorphs of the title tetra-kis-substituted pyrazine carb-oxy-lic acid, 3,3',3,3'-[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene))tetra-kis-(sulfanedi-yl]tetra-propionic acid, C20H28N2O8S4, (H4L1), have been obtained, H4L1_A and H4L1_B. VU0463271 chemical structure Each structure crystallized with half a mol-ecule in the asymmetric unit of a triclinic P unit cell. The whole mol-ecules are generated by inversion symmetry, with the pyrazine rings being located about inversion centers. The crystals of H4L1_B were of poor quality, but the X-ray diffraction analysis does show the change in conformation of the -CH2-S-CH2-CH2- side chains compared to those in polymorph H4L1_A. In the crystal of H4L1_A, mol-ecules are linked by two pairs of O-H⋯O hydrogen bonds, enclosing R 2 2(8) ring motifs forming layers parallel to plane (100), which are linked by C-H⋯O hydrogen bonds to form a supra-molecular framework. In the crystal of H4L1_B, mol-ecules are also linked by two pairs of O-H⋯O hydrogen bonds enclosing R 2 2(8) ring motifs, howen inversion center. Two symmetry-related acid groups are deprotonated and the charges are compensated for by two potassium ions.The crystal structures of three benzimidazole esters containing aryl or heterocyclic substituents at position 2 are reported, and all three exhibit disorder of mol-ecular entities. In ethyl 1-methyl-2-[4-(prop-2-yn-oxy)phen-yl]-1H-benzimidazole-5-carboxyl-ate, C20H18N2O3, (I), the prop-2-yn-1-oxyphenyl unit is disordered over two sets of atomic sites having effectively equal occupancies, 0.506 (5) and 0.494 (5). The propyl substituent in ethyl 1-propyl-2-(pyren-1-yl)-1H-benzimidazole-5-carboxyl-ate, C29H24N2O2, (II), is disordered over two sets of atomic sites having occupancies 0.601 (8) and 0.399 (8), and the ester unit in ethyl 1-methyl-2-(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1H-benzimidazole-5-carboxyl-ate, C21H19ClN4O2 (III), is disordered over two sets of atomic sites having occupancies 0.645 (7) and 0.355 (7). In each of the C-H⋯π(arene) hydrogen bonds in (I), the donor and acceptor form parts of different disorder components, so that no continuous aggregation is possible. The mol-ecules of (II) are linked by a single C-H⋯O hydrogen bond into C(10) chains, which are linked into sheets by a π-π stacking inter-action, whereas those of (III) are just linked into C(13) chains, again by a single C-H⋯O hydrogen bond. Comparisons are made with the structures of some related compounds.The asymmetric unit of the title compound, C15H12Br2F3NO2, consists of two crystallographically independent mol-ecules. In both mol-ecules, the pyrrolidine and tetra-hydro-furan rings adopt an envelope conformation. In the crystal, mol-ecule pairs generate centrosymmetric rings with R 2 2(8) motifs linked by C-H⋯O hydrogen bonds. These pairs of mol-ecules form a tetra-meric supra-molecular motif, leading to mol-ecular layers parallel to the (100) plane by C-H⋯π and C-Br⋯π inter-actions. Inter-layer van der Waals and inter-halogen inter-actions stabilize mol-ecular packing. The F atoms of the CF3 groups of both mol-ecules are disordered over two sets of sites with refined site occupancies of 0.60 (3)/0.40 (3) and 0.640 (15)/0.360 (15). The most important contributions to the surface contacts of both mol-ecules are from H⋯H (23.8 and 22.4%), Br⋯H/H⋯Br (18.3 and 12.3%), O⋯H/H⋯O (14.3 and 9.7%) and F⋯H/H⋯F (10.4 and 19.1%) inter-actions, as concluded from a Hirshfeld surface analysis.Twinning by pseudo-merohedry is a common phenomenon in small-mol-ecule crystallography. In cases where twin-component volume fractions are markedly different, structure solution is often no more difficult than for non-twinned structures of similar complexity. When twin-component volume fractions are similar, however, structure solution can be much more of a problem. This paper presents hints and tips for such cases by means of three worked examples. The first example presents the most common (and simplest) case of a two-component pseudo-ortho-rhom-bic twin. The second example describes structure solution of a reticular threefold pseudo-hexa-gonal twin that benefits from use of an unconventional space-group setting. The third example covers structure solution of a reticular fourfold pseudo-tetra-gonal twin. All three structures are ultimately shown to be monoclinic crystals that twin as a consequence of unit-cell metrics that mimic those of higher symmetry crystal systems.
Sub-Saharan Africa continues with very low hepatitis B (HBV) birth dose vaccination coverage. To guide policy on HBV vaccine for newborns, we explored perceptions, barriers and preferences of pregnant women regarding HBV and the HBV birth dose vaccination.
We conducted eight focus groups discussions (FGDs) among 70 pregnant women, stratified by rural-urban residence, age and education level, using a structured focus group discussion guide to explore birth dose awareness, perceptions, barriers and preferences. Data were transcribed, coded and analysed using framework analysis.
Perceptions related to HBV and liver cancer causes and prevention were diverse; most FGD participants did not perceive illnesses as distinctly different. Older women-groups, both urban and rural, had never heard about HBV, but were aware of liver cancer, viewing the disease as fatal. No FGD participants were aware of HBV birth dose. Concerns included vaccine safety, its availability to women who deliver outside the health system and mistrust in health-care worker (HCWs) when handling newborns. Rural-dwelling groups perceived absence of HBV services, while FGDs with young participants believed vaccine side-effects hampered birth dose planning. Most women-groups preferred (i) oral to injectable vaccines; (ii) receiving birth dose education during antenatal, to media-based education; (iii) that newborns receive the birth dose immediately after delivery in the mother's presence.
Although the birth dose is acceptable among pregnant women, planners need to continuously engage them as key stakeholders during planning to address concerns, in order to raise confidence, maximize uptake and strengthen HBV eradication efforts.
Although the birth dose is acceptable among pregnant women, planners need to continuously engage them as key stakeholders during planning to address concerns, in order to raise confidence, maximize uptake and strengthen HBV eradication efforts.