One equivalent electrical circuit is applicable to model the interface between the passive surface layer on an orthopaedic alloy and a biosimulating aqueous solution

The objective of this study was to test the hypothesis that there is one model for the interface between the passive layer on the surface of an orthopaedic alloy and an electrolyte that has clinical relevance. To this end, electrochemical impedance spectroscopy measurements were made on mechanically-polished test specimens fabricated from three orthopaedic alloys [two Ti-based ones (Ti-6Al-4V and Ti-13Nb-13Zr) and a very-low-nickel austenitic stainless steel, Biodur 108] while they were immersed in phosphate buffered saline (PBS) solution, at 37+/-1 degrees C, over a period of 25 d. Through a statistical comparison between the experimental results (Nyquist and Bode plots) and those computed using seven different equivalent electrical circuits (each representing a different model of the aforementioned interface), it was found that one circuit (comprising an arrangement of three resistances and three capacitances in series with a resistor representing the solution resistance) provided the best-fit in all three alloy surface-PBS solution systems, thus providing support for the working hypothesis. The variation of each of the circuit elements with time of immersion of the specimen in the PBS solution and the study limitation are discussed.     

A new algorithm in the differential diagnosis of wide complex tachycardia.

A correct electrocardiographic diagnosis of the mechanism ofa wide complex tachycardia (WCT) is important when institutingemergent therapy and for long-term prognostic and therapeuticconsiderations. While any algorithm has the risk of oversimplifyinga complex problem, it is absolutely essential to have an initialstrategy for the acute evaluation of an arrhythmia. Causes of wide QRS tachycardia include (1) supraventriculartachycardia (SVT) with pre-existing or functional bundle branchblock, including sinus tachycardia, atrial tachycardia, atrialflutter, atrial fibrillation (AF) and AV nodal re-entry tachycardia,(2) orthodromic circus movement tachycardia with pre-existingor functional bundle branch block, (3) SVT with conduction overan accessory pathway, (4) Antidromic circus movement tachycardiausing an accessory pathway in the anterograde direction andAV     

Endometrial aspiration cytology in dysfunctional uterine bleeding

Aspiration cytology is a safe simple and reliable technique without any complication This can be used as a safe and reliable out patient procedure with minimum discomfort to the patient. The use of a cannula as a device for endometrial aspiration provides adequate material for cytological examination. So the present study was undertaken, to assess the ease of collection of endometrial material and to assess the relative compatibility of aspiration cytology and histopathology.