The crystal structures of bis-guanidinium tetrachlorozincate(II) and bis-guanidinium tetrabromozincate(II) have been determined by X-rays. Both crystal structures are highly isomorphous; the ...descriptors of the isomorphism phenomenon are discussed and applied to the present case. The zinc ions are tetrahedrally coordinated. An extensive network of hydrogen bonds determine crystal packing. In each structure, two symmetrically independent cations exhibit quite different hydrogen bond patterns. These patterns are described and discussed in terms of graph set analysis.
The macrocyclic amine, 1,5,9,18,22,26-hexaaza 11.11-p-cyclophane (1) contains two dipropylenetriamine units which make the molecule highly basic. Owing to this basicity, 1 can be highly protonated in ...acidic media and can form supramolecular assemblies with different anions. Two new supramolecular structures arise from self-assembly of the salt of 1 with fumaric acid and of the N-methyl derivative of 1.
Literature data about the effects of tobacco smoke constituents in pregnancy are reviewed. Analysis on the authors material comprises 73 smoking and 70 non-smoking women in pregnancy. In the former ...group the natal body weight of new born is by 308 g lower and the placental-fetal index by 0.02 higher with no differences in the body weight increase of smoking and non-smoking women in pregnancy.
This paper presents a possibility of non-invasive diagnosis of fetal anemia based on the Doppler assessing of peak systolic velocity (PSV) in the fetal middle cerebral artery. The results of Doppler ...measurements were compared with fetal peripheral blood count estimated after cordocentesis.
Doppler measurements of blood flow velocity in the fetal middle cerebral artery were performed in years 2000 and 2001 in 22 pregnancies complicated by maternal blood group alloimmunisation. Gestation age varied from 27 to 36 weeks, the mean gestation age was 32 weeks. Depending on hemoglobin concentration in the fetal blood sample the severity of anemia was divided into three groups: severe anemia (Hb = < 7 g%), middle (Hb = = 8-10 g%) and light (Hb = = 10-12 g%). The fourth group consisted of fetuses without anemia (Hb > 12 g%). The results were statistically analyzed to estimate correlation between the Doppler blood flow indexes (PI, RI, SD and PSV) in the middle cerebral artery and the peripheral blood count (Hb, Ht, erythrocyte count) of fetal blood received by cordocentesis. Using T-Student-test the differences of average maximal blood flow velocities and mean Doppler indexes in the group of fetuses with severe anemia (Hb < 7 g%) and fetuses without anemia (Hb > 12 g%) were compared.
Highest (negative) correlation was found between the peak systolic velocity and the fetal hemoglobin concentration. The correlation index was -0, 85, which means the higher the peak systolic velocity the lower the hemoglobin concentration. The difference between the mean peak systolic velocity in the group of fetuses with severe anemia and the group without anemia was statistically significant (p < 0.001). However, there was no statistical significant difference in the mean peak systolic velocity between the group with middle anemia (Hb = 10-12 g%) and the group without anemia (Hb > 12 g%).
Doppler ultrasonography with the measurement of peak systolic velocity in the middle cerebral artery is a good method in evaluating of fetal peripheral blood count. Non-invasive peak systolic velocity measurements in the middle cerebral artery allow to assess the fetal hemoglobin concentration and also to reduce the count of diagnostic cordocentesis.
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