The broad band X-ray spectrum of the lowmass X-ray binary (LMXB) GS 1826-238 was measured with the narrow-field instruments on BeppoSAX on April 6 and 7, 1997. The spectrum is consistent with the Comptonization of a 0.6 keV thermal spectrum by a hot cloud of temperature equivalent kT = 20 keV. During the observation two type I X-ray bursts were detected. From the bursts an upper limit to the di...

We read with great interest the article titled “Intestinal ischemia after laparoscopic cholecystectomy” in the most recent issue of JSLS authored by Drs Leduc and Mitchell. In their manuscript, the authors describe their experience with a case of mesenteric vascular catastrophe after a laparoscopic procedure. In addition, the authors summarize the other reported cases they were able to find as ...

The aim of this study was to assess the prevalence and severity of dental fluorosis in permanent teeth and its association with dental caries in a group of school children living in a nonfluoridated community of Wielkopolska (Poland). The sample consisted of 470 children aged 6–14 years. Dental fluorosis was described using the Thylstrup and Fejerskov Index (TFI). Dental caries experience was a...

UNLABELLED Odontogenic tumors are neoplasms that develops exclusively in the gnathic bones; they originate from odontogenic tissues, by epithelial or mesenchymal proliferation, or both. AIM To evaluate the incidence of odontogenic tumors in a specific institution, and to compare these findings with other studies in the literature. STUDY FORMAT: A cross-sectional cohort retrospective study. ...

2.7. Redox Deprotections 221 3. Thiol Protecting Groups 223 4. Carboxy Protecting Groups 223 4.1. Protection 224 4.2. Deprotection 226 5. Carbonyl Protecting Groups 227 5.1. Acetals 227 5.1.1. Protection 227 5.1.2. Deprotection 231 5.2. Dithioacetals 233 5.2.1. Protection 233 5.2.2. Deprotection 235 5.3. 1,3-Oxathiolanes 237 5.4. 1,1-Diacetates (Acylals) 238 5.4.1. Protection 238 5.4.2. Deprote...

Critical views are presented on some nucleo-cosmochronological questions. Progress has been made recently in the development of the 187 Re-187 Os cosmochronometry. From this, there is good hope for this clock to become of the highest quality for the nuclear dating of the Universe. The simultaneous observation of Th and U in ultra-metal-poor stars would also be a most interesting prospect. In co...

The most common isotope, plutonium-239, is produced when the most common isotope of uranium, uranium-238, absorbs a neutron and then quickly decays to plutonium. It is this plutonium isotope that is most useful in making nuclear weapons, and it is produced in varying quantities in virtually all operating nuclear reactors. As fuel in a reactor is exposed to longer and longer periods of neutron i...