Abstract Introduction In sphenoid sinuses with ill-defined carotid bony landmarks, accidental injury of the internal carotid artery (ICA) remains one of the most challenging complications, which is particularly reported in the endoscopic endonasal transsphenoidal approaches (EETAs). Objectives To describe an anatomical model for the endoscopic orientation of the juxta-pituitary segment of the ICA in relation to the lateral opticocarotid recess (OCR) as a nearby bony landmark. Methods Dissection was performed progressively, simulating the EETA, in twenty fresh adult cadavers. After reducing the posterior and lateral walls of the sphenoid sinuses, various measurements were taken from both lateral OCRs to “contact points” on the juxta-pituitary segment of the ICA and lateral margins of the pituitary gland. Results The current results have enabled us to divide the region between the lateral OCRs into 3 compartments: 2 lateral parasellar compartments contain juxta-pituitary segments of the ICA with a mean width of 8 mm and a narrow range from 7 mm to 10 mm; and a central intercarotid sellar compartment represents the safe region for bone drilling, showing widely variable widths ranging from 9 mm to 20 mm. In all specimens, the variation in the width of the intercarotid compartment correlated with the distance between both lateral OCRs. Conclusion The present study improves surgeon awareness of the variations in the course of the ICA through the EETA along sphenoid sinuses with ill-defined bony landmarks. An appreciation of the measurements taken in the present study can help in operative training, and can also provide a base for future studies to confirm ICA courses associated with a higher risk of injury.

Abstract Seismic tomography has been extensively used in geophysics for different purposes, including geological mapping, characterisation of inner earth structure and prospecting for oil and gas. In geophysics, seismic or electromagnetic waves are commonly used to provide tomographic information. In the geotechnical area, seismic tomography is emerging as a promising technique that can be used to determine the spatial variability of shear wave velocities and hence the small strain stiffness of geomaterials, especially when used in the centrifuge where in-situ stress conditions can be mimicked closely. This paper describes the development of a seismic tomography technique in the centrifuge. This technology can be used to image variations of soil stiffness under various mechanical, chemical and physical conditions. The paper describes the various components of the system, which includes arrays of small-size bender elements, hardware and software used to transmit, receive and acquire the shear wave signals during a centrifuge test. The paper illustrates the performance of the system at both 1g and in the centrifuge. Results of tomographic inversion performed on travel-time data obtained from these tests are discussed.

Preparation of quinolinyl-3-oxopropanoic acid 2 was accomplished by hydrolysis of pyranoquinolinedione 1 in aqueous alkaline medium. The chemical behavior of this β-keto acid 2 towards nitrosation, coupling with a diazonium salt, esterification, condensation with 2,2-dimethoxyethanamine, hydrazinolysis, Knoevenagel condensation with isatine, salisyaldehyde, 3-formylquinolones, and 3-formylchromone, was investigated. Also many of the products of these reactions were found obtainable using either pyranoquinolinedione 1 or β-keto acid 2, under the same conditions.

La preparación del ácido quinolinil-3-oxopropanoico 2 se realizó por hidrólisis de la piranoquinolindiona 1 en medio acuoso alcalino. Se investigó el comportamiento químico de este β-cetoácido 2 en reacciones de nitrosación, acoplamiento con sales de diazonio, esterificación, condensación con 2,2-dimethoxyethanamine, hidrazinólisis, condensación de Knoevenagel con isatina, salicilaldehido, 3-formilquinolones y 3-formilchromonas. Muchos de los productos de estas reacciones pueden obtenerse mediante el uso ya sea de la piranoquinolindiona 1 o del β-cetoácido 2, bajo las mismas condiciones.

A series of novel bis-heterocyclic ethers, containing 4H-pyrido[1,2-a]pyrimidin-4-one along with other five and six-membered heterocyclic rings, was obtained utilizing ethyl [(4-oxo-4H-pyrido[1,2-a]pyrimidin-2-yl)oxy]acetate (1), [(4-oxo-4H-pyrido[1,2-a]pyrimidin-2-yl)oxy]acetic acid (2) and/or [(4-oxo-4H-pyrido[1,2-a]pyrimidin-2-yl)oxy]acetohydrazide (3). Reaction of ester 1 with some ortho-hydroxy-aldehydes furnished the corresponding pyrido-pyrimidyloxypyrones. Reaction of ester 1 or acid 2 with 1,2-diamines led to some imidazoles. Also, some pyrazole, triazole, and oxadiazoline derivatives have been prepared from hydrazide 3.

Se preparó una serie de novedosos éteres bis-heterocíclicos que contienen el anillo de 4H-pirido[1,2-a]pirimidin-4-ona, unido con anillos heterocíclicos de seis miembros, empleando [(4-oxo-4H-pirido[1,2-a]pirimidin-2-il)oxi]acetato de etilo (1), ácido [(4-oxo-4H-pirido[1,2-a]pirimidin-2-il)oxi]acético (2) o [(4-oxo-4H-pirido[1,2-a]pirimidin-2-il)oxi]acetohidrazida (3). La reacción del éster 1 con algunos orto-hidroxi-aldehidos proporcionaron las piridopirimidiloxipironas correspondientes. La reacción del éster 1 o el ácido 2 con 1,2-diaminas condujeron a algunos imidazoles. Asimismo, se prepararon algunos derivados de pirazol, triazol y oxiadiazolina a partir de la hidrazina 3.