Search results for "Orbital"

Conformations and Energetics of Sulfur and Selenium Diimides

2003

The geometries and energetics of different conformations of sulfur and selenium diimides E(NR) 2 (E = S, Se; R = H, Me, 'Bu, C 6 H 3 Me 2 -2,6, SiMe 3 ) have been studied by using various ab initio and DFT molecular orbital techniques. The syn,syn conformation is found to be most stable for parent E(NH) 2 , but in general, the preferred molecular conformation for substituted chalcogen diimides is syn,anti. In the case of E(NH) 2 the present calculations further confirm that syn,syn and syn,anti conformations lie energetically close to each other. From the three different theoretical methods used, B3PW91/6.31G * proved to be the most suitable method for predicting the geometries of chalcogen…

The Role of Orbital Symmetries in Enforcing Ferromagnetic Ground State in Mixed Radical Dimers

2018

One of the first steps in designing ferromagnetic (FM) molecular materials of p-block radicals is the suppression of covalent radical-radical interactions that stabilize a diamagnetic ground state. In this contribution, we demonstrate that FM coupling between p-block radicals can be achieved by constructing mixed dimers from different radicals with differing symmetries of their singly occupied molecular orbitals. The applicability of this approach is demonstrated by studying magnetic interactions in organic radical dimers built from different derivatives of the well-known phenalenyl radical. The calculated enthalpies of dimerization for different homo- and heterodimers show that the formati…

Discovery of slow X-ray pulsations in the high-mass X-ray binary 4U 2206+54

2008

Context. The source 4U 2206+54 is one of the most enigmatic high-mass X-ray binaries. In spite of intensive searches, X-ray pul- sations have not been detected in the time range 10−3–103 s. A cyclotron line at ∼30 keV has been suggested by various authors but never detected with significance. The stellar wind of the optical companion is abnormally slow. The orbital period, initially reported to be 9.6 days, disappeared and a new periodicity of 19.25 days emerged. Aims. The main objective of our RXTE monitoring of 4U 2206+54 is to study the X-ray orbital variability of the spectral and timing parameters. The new long and uninterrupted RXTE observations allow us to search for long (∼1 h) puls…

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…

Update in minimally invasive periorbital rejuvenation with a focus on platelet-rich plasma: A narrative review.

2020

Background The periorbital region is among the first areas to be affected by the process of aging, which is influenced by genetic and constitutional factors. As the region plays an important role in overall facial appearance, rejuvenation of the area has immense cosmetic benefit and various treatment modalities have been used to achieve the same. Aims This article reviews commonly used non-surgical and minimally invasive modalities for periorbital rejuvenation. Methods The literature research considered published journal articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles.…

The 2016 European Thyroid Association/European Group on Graves' Orbitopathy Guidelines for the Management of Graves' Orbitopathy

2015

Graves' orbitopathy (GO) is the main extrathyroidal manifestation of Graves' disease, though severe forms are rare. Management of GO is often suboptimal, largely because available treatments do not target pathogenic mech anisms of the disease. Treatment should rely on a thorough assessment of the activity and severity of GO and its impact on the patient's quality of life. Local measures (artificial tears, ointments and dark glasses) and control of risk factors for progression (smoking and thyroid dysfunction) are recommended for all patients. In mild GO, a watchful strategy is usually sufficient, but a 6-month course of selenium supplementation is effective in improving mild manifestations …

Somatostatin-Rezeptor-Szintigraphie bei endokriner Orbitopathie

1994

Somatostatin receptor scintigraphy with 111In-labeled octreotide proves to be a very sensitive diagnostic tool for evaluation of inflammative activity in endocrine ophthalmopathy (EO). The results of somatostatin receptor scintigraphy (SRS) in 40 patients with EO show a high orbital accumulation of 111In-octreotide in clinically active EO (4 h-median/orbit-brain-ratio: 12.6; controls 4 h-median: 5.8) Patients with clinically inactive EO (4 h-median: 7.1) show a similar orbital accumulation of radioactivity compared to controls. 5 patients with active orbital myositis also revealed an even higher orbital accumulation of radioactivity (4 h-median: 42.3). The diagnostic value of SRS lies in it…

Patients' cosmetic satisfaction, pain, and functional outcomes after supraorbital craniotomy through an eyebrow incision

2014

Object The supraorbital approach through an eyebrow incision offers the opportunity to access a wide variety of lesions of the anterior, middle, and even the posterior fossa. The minimally invasive keyhole craniotomy limits brain exploration and retraction and offers the potential for improved surgical outcomes and reduced approach-related complications. Patient satisfaction, however, has not yet been reported in the literature. Methods From January 2002 through December 2011, the lead author (R.R.) used a supraorbital approach through an eyebrow incision for 418 patients with cerebral aneurysms, brain tumors or cystic lesions, and other miscellaneous pathological conditions. For 408 of th…

Improvements in the diagnosis and surgical management of lesions in and around the orbit

1977

Radiotherapy for Graves’ ophthalmopathy

2000

The interest in the treatment of benign diseases with radiation therapy has grown particularly in the Western part of the world. In 1996, a questionnaire was sent to 1348 institutes worldwide listed in the directory of the Society for Therapeutic Radiology and Oncology asking whether the respondents considered a list of 28 most common benign disorders as being a good indication for orbital radiotherapy.1 Questions concerned the frequency of such treatments and the treatment schedules used. The prevention of keloid formation was the most widely accepted indication, followed by Graves’ ophthalmopathy. Thus, radiotherapy for this orbital disorder is generally accepted and applied worldwide.