Search results for " retraction"

Examples of proper k-ball contractive retractions in F-normed spaces

2007

Abstract Assume X is an infinite dimensional F -normed space and let r be a positive number such that the closed ball B r ( X ) of radius r is properly contained in X . The main aim of this paper is to give examples of regular F -normed ideal spaces in which there is a 1-ball or a ( 1 + e ) -ball contractive retraction of B r ( X ) onto its boundary with positive lower Hausdorff measure of noncompactness. The examples are based on the abstract results of the paper, obtained under suitable hypotheses on X .

Endoscopic dissection of dura and craniotomy with minimal trephines: a preliminary series.

1998

The first nine clinical cases using endoscopic dissection of dura and craniotomy with minimal trephines were performed from June to August 1997 after trial dissection of 19 fresh cadavers conducted at the University of Brno's Pathology Institute in the Czech Republic. These procedures involved the refinement of craniofacial and intracranial surgical techniques using the endoscope and prototype instruments. These dissections demonstrated that intracranial structures can be explored using an endoscope without encumbrance, and that major craniofacial surgeries may also be performed with minor incisions and minimal craniotomies. Furthermore, we seek to illustrate that use of the endoscope in cr…

In-vivo effects of flapless osteopuncture-facilitated tooth movement in the maxilla and the mandible.

2018

Background This study aimed to investigate the effects of a minimally invasive, flapless procedure to enhance tooth movement in both jaws and to determine whether this triggers the acceleration when repeated monthly. Material and methods The sample consisted of thirty-two individuals whose orthodontic treatment required canine retraction. They were divided into an experimental group and control group. Osteopunctures were performed using orthodontic mini-screws at the distal aspects of the canine teeth at the beginning and on the fourth week of distalization in the experimental group. The control group was treated with conventional mechanics. All canines were retracted. The rates of canine d…

Vertical gingival display changes associated with upper premolars extraction orthodontic treatment : a prospective clinical trial

2020

Background Extraction of upper bicuspids have been anecdotally blamed to increase the vertical gingival display (VGD) anteriorly. However, the extraction may be needed in some cases in order to correct the underlying orthodontic problem. Objectives: To investigate and compare vertical gingival display (VGD) changes associated with upper (first vs second) premolars extraction during orthodontic treatment. Material and Methods Design: A prospective clinical trial. Setting: Postgraduate dental teaching clinics at Jordan University of Science and Technology (JUST). Sample population: Sixty orthodontic patients were included in the study. They were treated with upper first or second premolars ex…

MR2370688 (2009e:46013) Navarro-Pascual, J. C.; Mena-Jurado, J. F.; Sánchez-Lirola, M. G. A two-dimensional inequality and uniformly continuous retra…

2009

Let X be an infinite-dimensional uniformly convex Banach space and let BX and SX be its closed unit ball and unit sphere, respectively. The main result of the paper is that the identity mapping on BX can be expressed as the mean of n uniformly continuous retractions from BX onto SX for every n >= 3. Then, the authors observe that the result holds under a property weaker than uniform convexity, satisfied by any complex Banach space, so that the result generalizes that of [A. Jim´enez-Vargas et al., Studia Math. 135 (1999), no. 1, 75–81; MR1686372 (2000b:46025)]. As an application the extremal structure of spaces of vector-valued uniformly continuous mappings is studied.

On k-ball contractive retractions in F-normed ideal spaces

2010

Let X be an infinite dimensional F-normed space and r a positive number such that the closed ball B_r(X) of radius r is properly contained in X. For a bounded subset A of X, the Hausdorff measure of noncompactness gamma(A) of A is the infimum of all $\eps >0$ such that A has a finite $\eps$-net in X. A retraction R of B_r(X) onto its boundary is called k-ball contractive if $\gamma(RA) \le k \gamma(A)$ for each subset A of B_r(X). The main aim of this talk is to give examples of regular F-normed ideal spaces in which there is a 1-ball contractive retraction or, for any $\eps>0$, a $(1+ \eps)$-ball contractive retraction with positive lower Hausdorff measure of noncompactness.

Preliminary study about the efficiency of diode laser compared with retraction cords used for exposing the finishing lines of dental abutments before…

2016

Surgical technique of the supraorbital key-hole craniotomy.

2003

BACKGROUND The enormous development of microsurgical techniques and instrumentation together with preoperative planning using the excellent preoperative diagnostic facilities available, enables neurosurgeons to treat more complicated diseases through smaller and more specific approaches. METHODS The technical details of the supraorbital key-hole craniotomy are described in this article as it has been evolving in our experience for more than 10 years. After an eyebrow skin incision with careful soft tissue dissection and single frontobasal burr-hole trephination, a supraorbital craniotomy is carried out with a diameter of about 1.5 x 2.5 cm. As a real frontolateral approach, the supraorbital…

An Evaluation of Fibrin(ogen) Determinants of Thromboelastography

2011

Abstract Abstract 2251 Thromboelastography (TEG) was used in ∼200 studies published in 2009, is mainly used for global blood coagulation assessment, and is thrombin and fibrinogen concentration-dependent. Reflecting the time course of fibrin polymerization, TEG measures lag time, rate, and maximum amplitude (MA) of clot stiffness, and is substantially enhanced by platelets. To identify more specific fibrin(ogen) determinants potentially relevant to interpretation we investigated MA under different TEG conditions. The procedure utilizes a polymethylmethacrylate (hydrophobic surface) cup and pin set, the cup oscillating through 4° 45' (6 cycles/minute). The pin (sensor) is suspended via a tor…

Unilateral Duane retraction syndrome. Report of a case.

1986

A case of Duane retraction syndrome (DRS) is reported. The major clinical subclasses of the syndrome and the most convincing pathogenetic hypothesis are briefly discussed.