RESUMO
A theoretical study of several new classes of polyhedral-based molecules has shown that these species display large calculated nonlinear optical responses. These new classes of molecules are based on charged aromatic subunits connected through polyhedral cluster bridges, such as closo-[1-(C(7)H(6))-12-(C(5)Me(4))C(2)B(10)H(10)]. These compounds show calculated first hyperpolarizabilities (beta) ranging from 6.5 to 8413.9 x 10(-30) cm(5) esu(-1). A basis for understanding the origin of these large responses is proposed based on the two-state model and consideration of the orbital and electronic features of the molecules. In general, the highest occupied molecular orbitals for these species are localized on the aromatic donor rings, such as the cyclopentadienyl system, while the lowest unoccupied molecular orbitals are largely on the aromatic acceptor rings, such as the tropylium system. The electronic properties of these polyhedral-based systems appear to be significantly different from the analogous organic [5.6.7]quinarene system (tropyliumcyclopentadienylbenzene). The organic quinarene appears to behave as a completely electron-delocalized system over all three rings while the polyhedral-based compounds can best be described as consisting of two relatively independent, highly polarized regions.
RESUMO
The synthesis and characterization of a series of new olefin-substituted closo-1,12-[C(2)B(10)H(12)] compounds is described. The reaction of deprotonated closo-1,12-dicarbadodecaborane with 7-methoxycycloheptatriene yields the cycloheptatriene-substituted carborane compound, closo-[1-(1-C(7)H(7))-12-(H)-C(2)B(10)H(10)] (3). Deprotonation of 3 with butyllithium and subsequent reaction with 3,4-dimethyl-2-cyclopenten-1-one was found to yield the bis-olefin-substituted carbinol compound [1-(1-C(7)H(7))-12-(C(5)H(4)-1-(OH)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (5) in good yield. Acidic dehydration of 5 quantitatively converted it into the simple bis-olefin cage compound [1-(1-C(7)H(7))-12-(C(5)H(3)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (6). Finally, thermal treatment of 6 in refluxing toluene was employed to prepare the isomerized cycloheptatriene compound [1-(4-C(7)H(7))-12-(C(5)H(3)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (7) in high yield. These compounds represent the first metal-free cyclopentadiene and bis-olefin large cluster species reported in which the C(5) ring is attached directly to the cage. The complete characterization of products by multinuclear NMR ((1)H, (11)B, and (13)C), infrared, UV-visible, and mass spectroscopic analyses is presented. The X-ray crystal structures of 3 and 7 are also reported. X-ray data for 3: triclinic system, space group P&onemacr; with cell constants a = 6.6807(3) A, b = 10.2939(3) A, c = 10.3962(4) A, alpha = 89.342(2) degrees, beta = 74.610(2) degrees, gamma = 83.373(2) degrees, Z = 2, R1 = 0.0487 (wR2 (all data) = 0.1272). X-ray data for 7: monoclinic system, space group P2(1)/c with cell constants a = 7.7207(7) A, b = 15.8730(14) A, c = 15.5493(13) A, beta = 99.146(2) degrees, Z = 4, R1 = 0.0761 (wR2 (all data) = 0.2050).
RESUMO
Intravenous nitroglycerin has recently come to the attention of obstetricians as a potent uterine relaxant. In the case presented, it was used to permit replacement of a tightly contracted, inverted uterus. Relaxation was rapid, effective, and associated with no adverse side effects.
Assuntos
Nitroglicerina/uso terapêutico , Complicações na Gravidez , Contração Uterina/efeitos dos fármacos , Doenças Uterinas/tratamento farmacológico , Adulto , Feminino , Humanos , Injeções Intravenosas , Gravidez , Doenças Uterinas/terapia , Prolapso Uterino/tratamento farmacológicoRESUMO
Since first reporting the association of hyperlipoproteinemia with inner ear disease in a study of 300 patients in 1973, I have continued to focus attention on the presence of lipid abnormalities in patients with inner ear dysfunction. With over 1,400 patients now identified with both abnormal lipids and inner ear symptoms, it has become increasingly apparent that most patients seen by otolaryngologists because of Meniere's disease come from that same large population group who are prone to obesity, maturity-onset diabetes, coronary artery disease, and atherosclerosis. These patients share the common problem of being unable to handle refined carbohydrates well. Based on the reports and studies of many authorities, a hyperinsulinism exists in these conditions. These patients are helped by replacing refined carbohydrates with complex carbohydrates having increased fiber. When these conditions can be identified in patients with Meniere's disease, dietary management has been found to be the most effective therapy.
Assuntos
Hiperinsulinismo/complicações , Hiperlipoproteinemias/complicações , Doença de Meniere/complicações , Humanos , Doença de Meniere/dietoterapia , Doença de Meniere/metabolismoRESUMO
Although disseminated geotrichosis is an unusual disease (to our knowledge, only six cases have been reported), Geotrichum candidum is not a very virulent fungus. In our case, there was neutrophillic phagocytosis of the arthrosphores of G candidum, with rapid clearance of the fungus from the plasma of a chronically ill patient whose immune defenses were still intact.
Assuntos
Geotrichum/isolamento & purificação , Fungos Mitospóricos/isolamento & purificação , Sepse/microbiologia , Adulto , Autopsia , Geotricose/patologia , Humanos , Abscesso Hepático/patologia , Masculino , Neutrófilos/análise , Neoplasias Pancreáticas/patologia , Nutrição Parenteral Total/efeitos adversos , Fagocitose , Escarro/microbiologiaRESUMO
Readily available tragal cartilage has been found to be a very beneficial autogenous graft source for construction of prostheses to correct those defects in the ossicular chain that frequently occur when the incudostapedial joint is destroyed by middle ear pathology, particularly by the retraction of the posterior, superior quadrant of the tympanic membrane against and/or around the incudostapedial connection. This is true whether there be only erosion of the incus just at the joint, or whether there is erosion of the entire long process of the incus together with the superstructure of the stapes. The various types of deformity and the particular tragal cartilage prosthesis tailored for each deformity, and designed for maximum gain in hearing, are presented together with representative pre- and postoperative audiograms for the variety of types.