Hericene is an unusual hexaolefin consisting of three 1,3-diene units located on a rigid bicyclo [2.2.2]octane framework that restricts the geometrical relationships of metal atoms bonded to these olefinic units.
View Article and Find Full Text PDFA woman in her early 30s presented to her primary care physician's office with hoarseness, joint pain and facial swelling. The objective evaluation revealed elevated inflammatory markers and angiotensin-1-converting enzyme, a chest radiograph with bilateral hilar prominence and a maxillofacial CT scan with diffuse inflammation in the upper airway. Otolaryngology evaluation revealed exophytic lesions diffusely within the nasal cavity, base of tongue, supraglottis, glottis and trachea.
View Article and Find Full Text PDFA 28-year-old woman with a history of congenital hip dysplasia was referred for evaluation of recurrent bronchitis. She had undergone left hip replacement with titanium implants 11 years prior to presentation. The patient reported frequent bouts of bronchitis, sinusitis, and left-sided nontender facial swelling that started after the hip replacement surgery.
View Article and Find Full Text PDFThe geometries and energetics of the -vertex polyhedral dicobaltadithiaboranes and dicobaltadiselenaboranes CpCoEBH (E = S, Se; = 8 to 12) have been investigated via the density functional theory. Most of the lowest-energy structures in these systems are generated from the ( + 1)-vertex most spherical deltahedra by removal of a single vertex, leading to a tetragonal, pentagonal, or hexagonal face depending on the degree of the vertex removed. In all of these low-energy structures, the chalcogen atoms are located at the vertices of the non-triangular face.
View Article and Find Full Text PDFMany binuclear nickel complexes have NiNi distances suggesting NiNi covalent bonds, including lantern-type complexes with bridging bidentate ligands. This DFT study treats tetragonal, trigonal, and digonal lantern-type complexes with the formamidinate, guanidinate, and formate ligands, besides some others. Formal bond orders (ranging from zero to two) are assigned to all the NiNi bonds on the basis of MO occupancy considerations.
View Article and Find Full Text PDFObjectives: To evaluate the difference in overall survival (OS) in patients with retromolar trigone squamous cell carcinoma (RMT SCC) treated with surgery alone versus surgery plus postoperative radiotherapy (PORT) versus surgery plus postoperative chemoradiotherapy (POCRT).
Materials And Methods: Retrospective cohort study of patients from 1,500 US facilities reporting to the National Cancer Database (NCDB) registry. Participants were adult patients treated with surgery as primary treatment modality for RMT SCC (n = 2,877).
The geometries, energetics, and preferred spin states of the second-row transition metal tris(butadiene) complexes (CH)M (M = Zr-Pd) and their isomers, including the experimentally known very stable molybdenum derivative (CH)Mo, have been examined by density functional theory. Such low-energy structures are found to have low-spin singlet and doublet spin states in contrast to the corresponding derivatives of the first-row transition metals. The three butadiene ligands in the lowest-energy (CH)M structures of the late second-row transition metals couple to form a CH ligand that binds to the central metal atom as a hexahapto ligand for M = Pd but as an octahapto ligand for M = Rh and Ru.
View Article and Find Full Text PDFThe structures and energetics of centered 10-vertex Ge@Ge₁₀(z) (z = -4, -2, 0, +2, +4) clusters have been investigated by density functional theory (DFT) for comparison with the previously studied isomeric empty 11-vertex Ge₁₁(z) clusters. For the cationic species (z = +2, +4) such centered Ge@Ge₁₀(z) structures are shown to be energetically competitive (within ∼1 kcal mol⁻¹) to the lowest energy isomeric empty Ge₁₁(z) structures. These Ge@Ge₁₀(z) structures can be derived from the lowest energy empty 10-vertex Ge₁₀(z-4) structures by inserting a Ge⁴⁺ ion in the center.
View Article and Find Full Text PDFThe authors review the case of a patient treated by Dr. Walter Dandy. When the patient was a young child he underwent two right transtemporal third ventriculostomies during which he sustained an unrecognized contralateral subdural hygroma and a chronic subdural hematoma with a mild infantile hemiparesis.
View Article and Find Full Text PDFThis simple method of achieving substantial pain control in patients with documented herpes zoster and postherpetic neuralgia has been effective in each of the patients in whom it has been used (the most recent 12 cases have been summarized for this report). It has been more effective than narcotic analgesics, oral anti-inflammatory analgesics, sedatives, tranquilizers, TENS, hypnosis and the wide variety of operative measures we have tried in the past. Although it was initially used pragmatically, there is now a reasonable rationale for its effectiveness that can be proposed based on more recent insights into the anatomy and neurophysiology of cutaneous nociceptors and the neuropharmacology of aspirin.
View Article and Find Full Text PDF