113 research outputs found
The endoscopic anatomy of the cochlear hook region and fustis: Surgical implications
The cochlear hook region can be considered as the interface between the middle and inner ear. The identification of surgically-relevant endoscopic landmarks of this anatomical entity and assessment of their clinical value is still lacking in the literature. Procedures like cholesteatoma surgery and minimal invasive endoscopic approaches to the lateral skull base may particularly benefit from these considerations. We hypothesize that the spatial orientation of anatomical landmarks in the cochlear hook can be expressed in angles and are reproducibly identifiable by transcanal otoendoscopy. Therefore, endoscopic dissection of the cochlear hook region was performed in 32 temporal bone specimens. Topographic anatomy was documented and analysed. We performed computed tomography of 28 specimens to assess the region in three-dimensional reconstructions. The mean angle between the round window and the basal scala tympani was assessed 25.9\ub0 in endoscopic and 28.2\ub0 in three-dimensionally reconstructed models. The fustis was recognised as a reliable landmark for the basal turn. A mean angle of 155.4\ub0 to the basal scala tympani was assessed. A slight bulging without obstruction of the basal turn was observed in 5 cases. The utility of the revealed anatomical details was assessed in minimal invasive endoscopic lateral skull base approaches. In conclusion, we described the angles between anatomical landmarks of the cochlear hook region. Moreover, the angle as recorded through an endoscope was found to be reliable compared to three-dimensional reconstructions from computed tomography
Discovering middle ear anatomy by transcanal endoscopic ear surgery: A dissection manual
The middle ear is located in the center of the temporal bone and bears a highly complex anatomy. The recently introduced exclusively endoscopic transcanal approach to the middle ear is a minimally invasive technique sparing the bone and mucosa of the mastoid bone, since the middle ear is accessed through the external auditory canal. This emerging method has several advantages over the traditional (microscopic) approaches to the middle ear such as the panoramic wide-angle views of the anatomy, the possibility to approach and magnify tiny structures, and the possibility of looking around the corner using angled endoscopes. The cadaveric dissection method presented here consists of an overview on the technical requirements and a precise description of a step-by-step protocol to discover the anatomy of the middle ear. Each step and anatomical structure is carefully described in order to provide a comprehensive guide to endoscopic ear anatomy. In our opinion, this is particularly important to any novice in endoscopic ear surgery as it provides thorough anatomical knowledge and may improve surgical skills
Entropy-driven cutoff phenomena
In this paper we present, in the context of Diaconis' paradigm, a general
method to detect the cutoff phenomenon. We use this method to prove cutoff in a
variety of models, some already known and others not yet appeared in
literature, including a chain which is non-reversible w.r.t. its stationary
measure. All the given examples clearly indicate that a drift towards the
opportune quantiles of the stationary measure could be held responsible for
this phenomenon. In the case of birth- and-death chains this mechanism is
fairly well understood; our work is an effort to generalize this picture to
more general systems, such as systems having stationary measure spread over the
whole state space or systems in which the study of the cutoff may not be
reduced to a one-dimensional problem. In those situations the drift may be
looked for by means of a suitable partitioning of the state space into classes;
using a statistical mechanics language it is then possible to set up a kind of
energy-entropy competition between the weight and the size of the classes.
Under the lens of this partitioning one can focus the mentioned drift and prove
cutoff with relative ease.Comment: 40 pages, 1 figur
Upscaled phase-field models for interfacial dynamics in strongly heterogeneous domains
We derive a new effective macroscopic Cahn-Hilliard equation whose
homogeneous free energy is represented by 4-th order polynomials, which form
the frequently applied double-well potential. This upscaling is done for
perforated/strongly het- erogeneous domains. To the best knowledge of the
authors, this seems to be the first attempt of upscaling the Cahn-Hilliard
equation in such domains. The new homog- enized equation should have a broad
range of applicability due to the well-known versatility of phase-field models.
The additionally introduced feature of systemati- cally and reliably accounting
for confined geometries by homogenization allows for new modeling and numerical
perspectives in both, science and engineering. Our results are applied to
wetting dynamics in porous media and to a single channel with strongly
heterogeneous walls
Cardiac dysfunction in pauci symptomatic human immunodeficiency virus patients: a meta-analysis in the highly active antiretroviral therapy era
Human immunodeficiency virus infection (HIV) has been associated with cardiac dysfunction that, if present, can negatively affect morbidity and mortality of HIV-infected patients. Unfortunately, many of the studies on this topic were performed before the highly active antiretroviral therapy (HAART) was established. Thus, we performed a comprehensive meta-analysis to critically appraise the incidence of cardiac dysfunction in HIV-infected pauci symptomatic patients. Medline, Cochrane Library, and Biomed Central were systematically screened for studies reporting on systolic and/or diastolic dysfunctions in HIV pauci-symptomatic patients. Baseline treatment and cardiac imaging data were appraised and pooled with random effect methods computing summary. At pooled analysis, including a total of 2242 patients from 11 studies, an overall average incidence of traditional cardiovascular risk factors was observed, while a low rate of previous coronary artery disease was reported. Incidence of systolic and diastolic left ventricular dysfunction was 8.33 (95 CI: 2.2014.25) and 43.38 (95 CI: 31.7355.03), respectively. Diastolic dysfunction was graded as first [31.85 (95 CI: 24.8543.73)], second [8.53 (95 CI: 2.1214.93)], and third degree [3.02 (95 CI: 1.784.27)]. At multivariate analysis, a high sensitivity C-reactive protein level 5 mg/L, active tobacco smoking and previous history of myocardial infarction were predictors of left ventricular systolic dysfunction [odd ratio 1.70 (95 CI: 1.032.77); 1.57 (95 CI: 1.032.34); and 15.90 (95 CI: 1.94329.00), respectively]. Hypertension (OR 2.30; 95 CI: 1.204.50) and older age (OR 2.50 per 10 years increase; 95 CI: 1.703.60) were predictors of left ventricular diastolic dysfunction (Figure 3). Systolic and diastolic dysfunction represent a common finding in pauci symptomatic HIV-infected patients, regardless to HAART
Cardiac dysfunction in pauci symptomatic human immunodeficiency virus patients: a meta-analysis in the highly active antiretroviral therapy era
Large deviations for the macroscopic motion of an interface
We study the most probable way an interface moves on a macroscopic scale from an initial to a final position within a fixed time in the context of large deviations for a stochastic microscopic lattice system of Ising spins with Kac interaction evolving in time according to Glauber (non-conservative) dynamics. Such interfaces separate two stable phases of a ferromagnetic system and in the macroscopic scale are represented by sharp transitions. We derive quantitative estimates for the upper and the lower bound of the cost functional that penalizes all possible deviations and obtain explicit error terms which are valid also in the macroscopic scale. Furthermore, using the result of a companion paper about the minimizers of this cost functional for the macroscopic motion of the interface in a fixed time, we prove that the probability of such events can concentrate on nucleations should the transition happen fast enough
A Multicenter Clinical Evaluation of Data Logging in Cochlear Implant Recipients Using Automated Scene Classification Technologies
Currently, there are no studies assessing everyday use of cochlear implant (CI) processors by recipients by means of objective tools. The Nucleus 6 sound processor features a data logging system capable of real-time recording of CI use in different acoustic environments and under various categories of loudness levels. In this study, we report data logged for the different scenes and different loudness levels of 1,366 CI patients, as recorded by SCAN. Monitoring device use in cochlear implant recipients of all ages provides important information about the listening conditions encountered in recipients' daily lives that may support counseling and assist in the further management of their device settings. The findings for this large cohort of active CI users confirm differences between age groups concerning device use and exposure to various noise environments, especially between the youngest and oldest age groups, while similar levels of loudness were observed
Outlining a new collaborative business model as a result of the green Building Information Modelling impact in the AEC supply chain
BIM (Building Information Modelling) technological push has enabled to integrate the design/construction outcomes of 3D-CAD along the product/service AEC (Architecture, Engineering and Construction) SC (supply chain) through an intelligent DMS (Data Management System) based on standard and interoperable data formats. The proposed end-to-end approach overcomes a typical AEC gap, enables the operationalisation of the sustainable/green building LCA (Life Cycle Assessment) and puts together new collaborative relationships with the owner, among SC stakeholders and with new forms of BIM procurement. The outlined collaborative business model is based on the Quality Control and Assurance framework and provides conceptual consistency to the reintroduction of the owner concerns/satisfaction in the SC, as well as enables consistent and accountable relationships between (smart)materials procurement and building specification. An expert’s focus group carried out a preliminary check of the model’s interest/applicability, resulting in recommendations for its further detailing and for propositions development into a systematic enquiring process.info:eu-repo/semantics/acceptedVersio
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