The use of acoustic microscopy to study the mechanical properties of glass-ionomer cement.

OBJECTIVES: The aim of the study was to investigate the relationship between microstructure, acoustic and mechanical properties of hardened dental cement samples, prepared with different powder/water ratios. METHODS: Glass-ionomer dental cement samples, prepared with a standard amount of cement powder and different amounts of water have been examined after being hardened. Surface microstructure and ultrasound, longitudinal and shear velocities were obtained with a scanning acoustic microscope. Conditional effective elastic modulus and Poisson's ratio have been calculated using longitudinal and shear sound velocity values. Then on the same samples elastic modulus and microhardness have been determined by standard tests. Additional samples have been used to determine compressive strength. RESULTS: Density; conditionally instantaneous elastic modulus; high-elasticity modulus and compression strength of the samples decrease when large amounts of water were used for their preparation. At the same time porosity and microhardness of the cement matrix increase. Acoustic parameters and parameters of elasticity, calculated on the basis of sound velocity, demonstrated changes, similar to those obtained in standard mechanical tests. SIGNIFICANCE: The established relation between microstructure, acoustic and mechanical parameters demonstrated a high capacity of acoustic microscopy application for non-destructive characterization of dental materials. A particular advantage of the acoustic microscopy is the opportunity to evaluate microstructure and mechanical properties on the same sample.     

Radiopharmaceuticals for radionuclidic diagnostics of bone pathology (review)

This review gives a brief outline of the history of development of radiopharmaceuticals (RPh) for radionuclide diagnostics of bone pathology. The advantages of RPh based on ^99mTc-diphosphonates are demonstrated.     

Substituted Amides and Hydrazides of Dicarboxylic Acids. Part 15. Synthesis and Hypoglycemic Activity of Some Amides and Acylhydrazides of Tetrachlorophthalic Acid

Pharmaceutical Chemistry Journal -     

Substituted Amides and Hydrazides of Dicarboxylic Acids. Part 17. Synthesis and Antibacterial and Anticonvulsant Activity of Some Amides and Acylhydrazides of Phthalic Acid

Pharmaceutical Chemistry Journal -     

Substituted Amides and Hydrazides of Dicarboxylic Acids. Part 16. Synthesis and Antibacterial Activity of Some Amides and Acylhydrazides of Succinic Acid

Pharmaceutical Chemistry Journal -     

Effect of corticosteroids on argyrophilic premedullary thymocytes

Cells in the premedullar zone of the thymus contain serotonin and catecholamines and show argyrophilicity in the Grimelius test. Their cytoplasm is packed with granules. Glucocorticoids (hydrocortisone) provoke an increase in the number of argyrophilic premedullary cells and in their content of serotonin and catecholamines. Mineralocorticoids induce a prolonged (1–14 days) increase in the number of argyrophilic premedullary cells, enhance their degranulation, and increase their contents of serotonin (2–3 fold) and catecholamines. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 10, pp. 461–464, October, 1996     

Visualization of patent foramen ovale by biplanar transesophageal echocardiography

Summary It is difficult for conventional transthoracic echocardiography (TTE), by which precise and accurate images of interatrial septum (IAS) can not be acquired, to diagnose patent foramen ovale (PFO) clearly. To evaluate the diagnostic value of biplanar transesophageal echocardiography (TEE) for PFO, TTE and biplanar TEE were performed simultaneously in 270 patients. It was found that in 7 patients patent foramen ovale was detected only through longitudinal planes of biplanar TEE. IAS, which consists of primitive septum and membrane of fossa ovalis, can be directly visualized by two-dimensional images of TEE; in patients with PFO, a dull color flow, which shunts from the right atria to the left atria through the gap between primitive septum and fossa ovalis, can be detected by color Doppler flow images. Furthermore, some right-to-left shunting microbubbles through the valve of patent fossa ovalis can be discovered by cardiac acoustic contrast echocardiography. In conclusion, biplanar TEE combined with color Doppler image and cardiac acoustic contrast facilitates a definite diagnosis of patent foramen ovale as the excellent anatomic images of IAS can be obtained from multiple views under this kind of performance.     

Pharmacokinetics of Controlled Release and Immediate Release Morphine Sulphate Tablets after a Single Dose and Multiple Doses in Chinese Volunteers

健康志愿者１０名，随机交叉口服硫酸吗啡控释片（ＣＲＭＳ）３０ｍｇ（３０ｍｇ×１）和硫酸吗啡普通片（ＩＲＭＳ）２０ｍｇ（１０ｍｇ×２），分别于服药前后各时点取静脉血，用ＧＣＭＳ测定血浆中吗啡含量。以药代软件程序处理，分别求得ＣＲＭＳ和ＩＲＭＳ的Ｃｍａｘ为１９．３８±３．８０和２１．２７±６．２１ｎｇ／ｍｌ；ｔｍａｘ为２．３６±０．３７ｈ和０．５５±０．１６ｈ；ｔ１／２β为３．５３±０．８７ｈ和３．０３±０．７４ｈ，曲线下面积ＡＵＣ为１４５．１５±１７．６５和９３．０８±１６．６５ｎｇ·ｈ／ｍｌ。癌症病人多次口服硫酸吗啡至稳态，ＣＲＭＳ和ＩＲＭＳ的峰浓度分别为２７．４３±０．３３ｎｇ／ｍｌ，２２．６８±０．１６ｎｇ／ｍｌ；谷浓度分别为１９．４５±１．４４ｎｇ／ｍｌ；１８．１４±０．４９ｎｇ／ｍｌ。