Mixed crystals composed of 1,2-bis(2-methyl-5-(p-methoxyphenyl)-3-thienyl)perfluorocyclopentene (1a) and 1,2-bis(5-methyl-2-(p-methoxyphenyl)-4-thiazolyl)perfluorocyclopentene (2a) were prepared, and their photochromic as well as light-driven bending performance was studied to reveal how shape changes of individual molecules cause the bending response. 1a and 2a molecules, having similar geomet...

We show how experimental values of the lifetime of the 1s level of pionium and of the difference between the energies of the 2s and 2p levels yield values of the elements aoc and acc respectively of the s-wave scattering matrix for the two-channel (π+π−, π0π0) system at the π+π− threshold. We then develop a method, using energy independent hadronic potentials which reproduce the best available ...

We report the first observation of stimulated emission of terahertz radiation from internal transitions of excitons. The far-infrared electromagnetic response of Cu2O is monitored via broadband terahertz pulses after ultrafast resonant excitation of three-dimensional 3p excitons. Stimulated emission from the 3p to the energetically lower 2s bound level occurs at a photon energy of 6.6 meV, with...

Oro-Antral Fistula is a communication between Maxillary Sinus and Oral Cavity, Dental diseases has been reported recently in 30% of maxillary sinusitis cases, The Pathophsiology of Odontogenic Maxillary Sinusitis is different than inflammatory maxillary sinusitis. The aim of this article is to highlight the etiology, symptoms and management of Odontogenic sinusitis in addition management of Oro...

introduction: this study was carried out to compare the capability of k-files with mtwo rotary file in terms of negotiation as well as depth of penetration in second mesiobuccal (mb2) canal of maxillary first molar. materials and methods: a total of 32 mb2 canal of maxillary first molars having different root curvatures (not more than 30 degree) and root lengths were selected and then detected ...

thorough knowledge of the morphology and internal anatomy of the root canal system is essential, because it determines the successful outcome of endodontic treatment. the main goal of endodontic treatment is to prevent apical periodontitis and/or to promote the healing of periapical lesion. presence of two canals or roots on the palatal side of the first maxillary molar has rarely been reported...

conclusions it was observed that the success and survival rate of maxillary molar immediate implant was relatively high and similar to those of conventional delayed implants. results immediate implants were most frequently used for incisor and premolar sites and there is very little data available on immediate implantation in the molar area. in this research, we reviewed all the existing papers...

The study compared the mathematical problems encountered by Brunei students in first year (Form 1 with no repeaters) and second year (Form 2 with many repeaters) of lower secondary school. Participants consisted of 67 Form 1s and 46 Form 2s. Results from the Wide Range Achievement Test and the Woodcock-Johnson Psycho-Educational Battery indicated that the students had wide ranging difficulties ...

We have studied the electronic structure of nanocrystalline NiO thin films, grown by radio-frequency magnetron sputtering under different experimental conditions, using x-ray absorption spectroscopy. The O 1s and Ni 2p spectra showed distinct changes as a function of O2 content in the plasma, which were reproduced with cluster model calculations. These changes are attributed to the incrementing...

Cholesterol granuloma (CG) is a tissue reaction in response to the accumulation of cholesterol crystals rarely found in the maxillary sinus. The etiopathogenesis of maxillary sinus CG remains unclear. We reviewed the literature and added two new reports of cholesterol granuloma in maxillary sinus related to endodontically treated maxillary posterior teeth. The first report refers to a 45-year-o...