Impact of particle size and morphology on zinc cation adsorption by hydroxyapatite and dentifrice containing hydroxyapatite / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the influence of particle size and morphology on zinc cation adsorption by hydroxyapatite (HA) and dentifrice containing HA.</p><p><b>METHODS</b>Four HAs with different particle sizes and morphologies, HA-containing dentifrice and blank dentifrice were prepared into suspensions of serial concentrations. Zinc ion solutions with an initial concentration of 10 mg/L was mixed with the suspensions and kept for 24 h for adsorption reaction. The zinc ion concentration in the supernatant was measured by inductively coupled plasma emission spectrometer and the sorption rate of zinc ion was calculated.</p><p><b>RESULTS</b>HA and HA-containing dentifrice with various particle sizes and morphologies were all capable of absorbing zinc ions from simulated waste water, and the adsorption rate of HA-containing dentifrice was 3%-10% higher than that of HA. HA with a particle size of 12 µm and a spherical morphology showed the strongest adsorption ability, followed by short bar-shaped HA with a particle size of 30 µm. Both Langmuir and Freundlich equation could simulate the sorption processes of HA dentifrice, while only Langmuir equation could simulate the sorption processes of HA.</p><p><b>CONCLUSION</b>Incorporation of HA in dentifrice can enhance zinc ion adsorption capacity of the material. The particle size and morphology of HA both affect the adsorption of zinc ions, and 12-µm HA particle with a spherical morphology has the best adsorption ability.</p>

Chemical constituents of Spatholobus suberectus / 中国天然药物

AIM@#To investigate chemical constituents of Spatholobus suberectus Dunn.@*METHODS@#Isolation and purification were carried out by column chromatographic methods. Compounds were characterized based on their physical characteristics and spectra data.@*RESULTS@#Seventeen compounds were isolated from ethanol extract of S. suberectus. The structures were elucidated as prestegane B (1), (2R, 3R)-buteaspermanol (2), (+)-medioresinol (3), (2R, 3R)-3,7-dihydroxyflavanone (4), benzeneethanol (5), 4, 7, 2'-trihydroxy-4'-methoxyisoflavanol (6), naringenin (7), blumenol A (8), protocatechuic acid ethyl ester (9), liquiritigenin (10), 7, 4'-dihydroxy-8-methoxy-isoflavone (11), 3, 5, 7, 3', 5'-pentahydroxyflavanone (12), protocatechuic acid (13), glycyroside (14), 8-methylretusin-7-O-β-D-glucopyranoside (15), 3, 3', 4', 5, 6, 7, 8-heptahydroxyflavan (16), and dulcisflavan (17).@*CONCLUSION@#All compounds are firstly isolated from the title plant and compounds 1, 3 were isolated from the Spatholobus genus for the first time.

Rapid analysis of metronidazole tablets by optic-fiber sensing technologies and the similarity of ultraviolet spectra / 药学学报

The paper is to report the development of an optic-fiber sensing technology method to analyze metronidazole tablets rapidly. In this fiber-optic sensing system, the light from source delivering to probe can be dipped into simple-handling sample solution, absorbed by the solution and reflected to the fiber-optic and detected in the detection system at last. Then the drug content can be shown in the screen from the ultraviolet absorption spectra and the consistency between that obtained by this method and that in China Pharmacopoeia can be compared. With regard to data processing, a new method is explored to identify the authenticity of drugs using the similarity between the sample map and the standard pattern by full ultraviolet spectrum. The results indicate that ultraviolet spectra of tablets can be obtained from this technology and the determination results showed no significant difference as compared with the method in China Pharmacopoeia (P > 0.05), and the similarity can be a parameter to identify the authenticity of drugs.

Research on anatomy of posterior tooth in the Beagle dog and mini-screw implant implantation / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The morphological characteristics of posterior tooth in the Beagle dog were investigated in order to provide reference to mini-screw implant (MSI) implantation in the root furcation site.</p><p><b>METHODS</b>Seventy posterior teeth of five Beagle dogs were collected and measured as follows: First, the greatest mesio-distal diameter AB of the crown was measured, which was perpendicular to the tooth long axis. Second, mesial cusp of maxillary posterior tooth or central cusp of mandibular was marked as the piont C, and CD which was equal and perpendicular to AB was drawn. The piont D was planned to be the reference point for MSI implantation. Finally, Dm, Dd and Df were measured, which were the distance from the point D to the mesial and distal root surface and root furcation.</p><p><b>RESULTS</b>The difference between the left and right sides teeth with the same name had no statistical significant (P > 0.05). The measurement results of all indices assumed a Gaussian distribution. The mean Dd was basically equal to Dm. All the average Df were more than 4 mm.</p><p><b>CONCLUSION</b>The point D could be used as a reference point for MSI implantation in the root furcation site of posterior tooth in the Beagle dog. The data of this study can provide certain reference for MSI implantation in the study of the biomechanics of anchorage stability, and provide certain reference for MSI implantation in the study of root repair after injury.</p>