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.     

阴囊皮瓣修复阴茎缺损的临床应用

目的探讨阴囊皮瓣修复阴茎大部分缺损的临床效果。方法对由不同原因引起阴茎缺损的17例患者，采用阴囊皮瓣进行修复。在阴囊根部两侧阴囊前动脉之间的无血管区剥离一腔隙，将延长后的阴茎海绵体经腔隙转移至阴囊皮瓣的下方，以包绕海绵体创面，皮瓣缝合后瘢痕在阴茎腹侧。结果切口均Ⅰ期愈合。术后随访患者1～9年，未出现皮瓣坏死现象，阴茎的外观及功能恢复较好。结论阴囊皮瓣的血运丰富、组织柔软、弹性好、伸缩性强，而且此手术切口隐蔽，是修复阴茎缺损较理想的皮瓣。     

循证医学与循证影像诊断学

近年来,循证医学(EBM)风靡全球,被公认为21世纪临床医学发展趋势。目前,循证医学的发展十分迅速,已广泛应用于医疗卫生的各个领域,形成了许多新的医疗模式,如循证保健(EBH)、循证诊断(EBD)、循证内科(EBIM)、循证外科(EBS)、循证妇产科(EBGO)、循证儿科(EBP)、循证护理(EBN)等,使现代临床医学实践与教学进入了一个崭新的历史阶段[1-3]。循证医学就是遵循客观证据的医学,影像医学是提供最佳证据的技术之一,在医学影像新技术、新方法层出不穷的今天,如何将循证医学的原理应用到影像诊断学,这是医学影像工作者面临的重要问题,应引起高度重视[4]。     

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.