Evaluation of the thyroid disorders in children with familial Mediterranean fever

Clinical Rheumatology - Although it is well-known that autoimmune thyroid diseases are more common in most of the autoimmune connective tissue diseases, the relationship between autoinflammatory...     

Vancomycin Containing PLLA/β-TCP Controls MRSA In Vitro

Background  

Osteomyelitis caused by Methicillin-resistant Staphylococcus aureus (MRSA) often requires surgery and prolonged systemic antibiotic treatment. Local antibiotic delivery systems of bioceramics or polymers have been developed to treat osteomyelitis. A disadvantage of biodegradable polymers is the initial burst of antibiotics into the environment; one advantage of bioceramics is its osteoconductivity. We therefore developed a vancomycin-containing poly-l-lactic acid/β-tricalcium phosphate (PLLA/β-TCP) composite to control antibiotic release and stimulate bone formation.     

The effect of acquired salivary pellicle on the surface free energy and wettability of different denture base materials

OBJECTIVE: The objective of the present study was to evaluate the effect of salivary coating on the wettability and surface free energy of different denture base materials. METHODS: Five acrylic resin and two metallic denture base materials were investigated. Ten specimens of each material (20 x 15x1.5mm) were fabricated and a standardized method was used for polishing the test specimens. Whole unstimulated saliva was collected from a single healthy donor. The wettability properties of the materials were tested before and after organic layer formation. The wetting forces were determined according to the Wilhelmy Plate Technique. Diiodomethane, ethylene glycol and formamide were used as probe liquids.The contact angles, Lifshitz-van der Waals surface energy components, Lewis acid-base surface energy components and total surface energies were calculated using the equations described in the paper. The significance of the differences in the experimentally determined surface energies of different denture materials are calculated by statistical methods. CONCLUSIONS: Light-cured acrylic resin was the most wettable material with a significant basic character. Organic layers decreased the total surface free energies of all materials and at the same time imparted a more basic character. The coatings had a homogenizing effect in terms of the surface free energy components of the denture materials, nevertheless, their adhesive properties were still influenced by the substrate employed.     

Microsurgical anatomy and surgical exposure of the cerebellar peduncles

A better understanding of the surgical anatomy of the cerebellar peduncles in different surgical approaches and their relationship with other neural structures are delineated through cadaveric dissections. We aimed to revisit the surgical anatomy of the cerebellar peduncles to describe their courses along the brain stem and the cerebellum and revise their segmental classification in surgical areas exposed through different approaches. Stepwise fiber microdissection was performed along the cerebellar tentorial and suboccipital surfaces. Multiple surgical approaches in each of the cerebellar peduncles were compared in eight silicone-injected cadaveric whole heads to evaluate the peduncular exposure areas. From a neurosurgical point of view, the middle cerebellar peduncle (MCP) was divided into a proximal cisternal and a distal intracerebellar segments; the inferior cerebellar peduncle (ICP) into a ventricular segment followed by a posterior curve and a subsequent intracerebellar segment; the superior cerebellar peduncle (SCP) into an initial congregated, an intermediate intraventricular, and a distal intramesencephalic segment. Retrosigmoid and anterior petrosectomy approaches exposed the junction of the MCP segments; telovelar, supratonsillar, and lateral ICP approaches each reached different segments of ICP; paramedian supracerebellar infratentorial, suboccipital transtentorial, and combined posterior transpetrosal approaches displayed the predecussation SCP within the cerbellomesencephalic fissure, whereas the telovelar approach revealed the intraventricular SCP within the superolateral recess of the fourth ventricle. Better understanding of the microsurgical anatomy of the cerebellar peduncles in various surgical approaches and their exposure limits constitute the most critical aspect for the prevention of surgical morbidity during surgery in and around the pons and the upper medulla. Our findings help in evaluating radiological data and planning an operative procedure for cerebellar peduncles.

     

Polymerization of styrene and methyl methacrylate by 2,5-dimethyl-2,5-dihydroperoxyhexane, 1. Bulk polymerization

A new polymerization initiator 2,5-dimethyl-2,5-dihydroperoxyhexane is used as an initiator for the polymerization of styrene and methyl methacrylate at 80°C. It is found that the rates of initiation for this initiator lie in-between those of di-tert-butyl peroxide and benzoyl peroxide for both monomers. The kinetic results show good agreement between dilatometric and gravimetric measurements for the polymerization of styrene. However, mostly oligomers were obtained at high initiator concentrations with methyl methacrylate. A narrow molecular weight distribution is observed from stress-relaxation measurements for the polystyrene samples obtained at high conversions.