7 research outputs found
Properties of Calcium Phosphate/Hydrogel Bone Grafting Composite on the Model of Diaphyseal Rat Femur’s Defect: Experimental Study
Background. The problem of bone defects replacement is relevant nowadays, that is why many scientists create new synthetic bone substitutes, but the ideal material has not been found so far.
The aims of the study: 1) to determine the suitability of the monocortical defect model in the rat femur diaphysis with additional prophylactic reinforcement with a bone plate for assessing the biological properties of implanted materials using the commercially available ChronOS material as an example; 2) to assess of the osteoconductive properties of composite materials based on poly(ethylene glycol)diacrylate and octacalcium phosphate with architecture Kelvin and gyroid types on the developed model.
Methods. A prospective study, level of evidence II. A monocortical defect of the rat femoral diaphysis (length 7 mm) was produced under anaesthesia in aseptic conditions and fixed with a polyetheretherketone plate and six titanium screws. In the control group, the defect was left empty. In other groups, blocks of one of three materials were implanted сhronOS and composites of poly(ethylene glycol)diacrylate and octacalcium phosphate with 3D-printed Kelvin and gyroid architectures. After 3 and 6 weeks, the rats were sacrificed, and histological examination of the defect zone was performed. The amount of newly formed bone tissue was histometricly assessed, followed by statistical processing of the results.
Results. All rats have reached the planned endpoint, and there were no infectious complications or loss of fixation. Histological examination of the defect zone revealed minimal bone growth in the Control group, rather slow bone formation in the Gyroid group, and statistically significantly more pronounced bone formation in the pores of the materials in the Kelvin and Chronos groups.
Conclusions. Bone defect in this model was not spontaneously filled with bone tissue and allowed us to study the biological properties of bone substitutes (the ability to biodegrade and osteoconductive properties). The osteoconductive properties of a composite material based on poly(ethylene glycol)diacrylate and octacalcium phosphate with a Kelvin architecture are higher than with a gyroid architecture and are comparable to that of the сhronOS
Magnetic Fields in the Milky Way
This chapter presents a review of observational studies to determine the
magnetic field in the Milky Way, both in the disk and in the halo, focused on
recent developments and on magnetic fields in the diffuse interstellar medium.
I discuss some terminology which is confusingly or inconsistently used and try
to summarize current status of our knowledge on magnetic field configurations
and strengths in the Milky Way. Although many open questions still exist, more
and more conclusions can be drawn on the large-scale and small-scale components
of the Galactic magnetic field. The chapter is concluded with a brief outlook
to observational projects in the near future.Comment: 22 pages, 5 figures, to appear in "Magnetic Fields in Diffuse Media",
eds. E.M. de Gouveia Dal Pino and A. Lazaria
Modular pyridine-type P,N-ligands derived from monoterpenes: Application in asymmetric Heck addition
Novel (diphenylphosphinophenyl)pyridine ligands (+)-8, (+)-15, (-)-21, and (-)-26 were synthesized from (-)-β-pinene, (+)-3-carene, (+)-2-carene, and (-)-α-pinene, respectively, via Kröhnke annulation as the key step, and shown to effect ≤88% ee in Heck addition (27→28). Ligands (+)-15 and (-)-21 are quasi-enantiomeric; ligands 8 and 26 can be prepared in both enantiomeric forms from (+)- and (-)-enantiomers of α- and β-pinene, respectively. © 2001 Elsevier Science Ltd
Duct Adenoma of the Breast as Background Process for Cholesterol Granuloma: Case Report and Literature Review
Cholesterol granuloma (CG) is an extremely rare benign condition that should be considered in the differential diagnosis of breast lesions suspected of being malignant. We present a case of a 55-year-old woman who presented with a nodule mass in the upper external quadrant of the right breast on a routine mammography examination. The described case is noticeable by the combination of multiple CGs in the lungs (with arterial hypertension and thrombocytopenia as a background) with breast presentation, which was associated ductal adenoma
Enantioselective allylation of α,β-unsaturated aldehydes with allyltrichlorosilane catalyzed by METHOX
α,β-Unsaturated aldehydes 6a-j undergo an enantioselective allylation with allylic trichlorosilanes 2a,b in the presence of METHOX (4) as a Lewis basic catalyst (≤10 mol %) to produce the homoallylic alcohols 7a-l at good to high enantioselectivity (83-96% ee). This study shows that the reactivity scope of METHOX can be extended from aromatic to nonaromatic aldehydes