The middle ear ossicles are only rarely preserved in fossil hominins. Here, we report the discovery of a complete ossicular chain (malleus, incus, and stapes) of Paranthropus robustus as well as additional ear ossicles from Australopithecus africanus. The malleus in both early hominin taxa is clearly human-like in the proportions of the manubrium and corpus, whereas the incus and stapes resembl...

OBJECTIVES To investigate intra- and postoperative outcomes of endoscopic stapes surgery. STUDY DESIGN Case series with chart review. SETTING Four tertiary care otologic centers. SUBJECTS AND METHODS Sixty-five subjects 18 years and older who underwent endoscopic stapes surgeries were analyzed. Variables analyzed included surgical techniques and intraoperative findings. Outcomes measured ...

BACKGROUND The stapes, an ossicle found within the middle ear, is involved in transmitting sound waves to the inner ear by means of the oval window. There are several developmental problems associated with this ossicle and the oval window, which cause hearing loss. The developmental origin of these tissues has not been fully elucidated. RESULTS Using transgenic reporter mice, we have shown th...

In conductive hearing loss caused by otosclerosis stapes, surgery is the generally accepted treatment of choice. Since the introduction of stapes surgery in the 1950’s many different approaches have been developed. All modern procedures aim at reconstruction of a functional, mobile ossicular chain and adequate sound transfer at the stapes footplate. In the last two decennia small fenestra stape...

Middle ear ossicle malformations are an uncommon event. Among them, the congenital absence of the stapes is a very rare condition that is seldom described in the literature. We report the cases of two women, aged 19 and 22 , who presented with a long history of conductive deafness. An exploratory tympanotomy was performed and the absence of the stapes superstructure and an abnormal position of ...

This paper presents the numerical simulation and experimental investigation on impact factors on premature failure of the self-lubricated piston rings in oil-free compressor. In this paper, the finite element method (FEM) was applied to study the non-uniform pressure distributions between the piston rings and the friction process between the self-lubricating piston rings and the cylinder wall, ...

OBJECTIVE The aim of this study was to evaluate the hearing results of revision stapes surgery performed because of previously failed operations and to determine the causes of failure. STUDY DESIGN Retrospective review of revision stapes operations. SETTING Tertiary referral center. PATIENTS Sixty-three consecutive revision stapes operations were performed in 56 patients over a period of ...

We are masters of the unsaid words, but slaves of those we let slip out. Winston S. Churchill The US health system is in the midst of a large (and now unpredictable) transformation. There are, in development, a large number of metrics to assess the quality and cost of cardiac care. Assuming these continue to be employed, they will impact on physician and hospital reimbursement, changing the inc...

Ogston & Stanier (1950, 1951, 1952) have referred to measurements made with a Couette viscosimeter. Since this viscosimeter can be constructed almost wholly in an ordinary laboratory workshop, and since it has proved to be convenient and accurate in CONSTRUCTION Drive. A type RQ synchronous motor, 73 rev./ min. (Drayton Regulator and IIistrument Co. Ltd.) is coupled by a stirrup coupling to the...