A transition metal oxofluoride offering advantages in electrocatalysis and potential use in applications.

The recently described solid solution (Co,Ni,Mn)3Sb4O6F6 has proved stable and efficient as a catalyst for electrocatalytic water oxidation. The end component Co3Sb4O6F6 was found to be most efficient, maintaining a current density of j = 10 mA cm(-2) at an overpotential of 443 mV with good capability. At this current density, O2 and H2 were produced in the ratio 1 : 2 without loss of faradaic current against a Pt-cathode. A morphological change in the crystallite surface was observed after 0.5 h, however, even after 64.5 h, the overall shape and size of the small crystallites were unaffected and the electrolyte contained only 0.02 at% Co. It was also possible to conclude from in situ EXAFS measurements that the coordination around Co did not change. The oxofluorides express both hydrophilic and hydrophobic surface sites, incorporate a flexible metalloid element and offer the possibility of a mechanism that differs from other inorganic catalytic pathways previously described.

Paediatric Crohn's disease: a radiological review.

Paediatric Crohn's disease can be a serious and complex condition which is not always easy to diagnose if it presents in an atypical manner. Although the pathological processes are the same in adults and children, the clinical presentation and disease distribution can be different in children. The impact of the disease can also be much more significant in a growing and developing child than in an adult. Numerous investigations are available to establish the diagnosis, define the complications and to demonstrate the extra-intestinal manifestations. Close cooperation is required between the clinician and radiologist when investigating a child suspected of having Crohn's disease or its symptoms to minimise the radiation dose and the psychological and physical trauma. We review the clinical and radiological aspects of Crohn's disease and discuss the imaging modalities available in diagnosing Crohn's disease and its complications and suggest an investigation pathway as used in our institution.

Pyridinium hydrobromide perbromide: a versatile catalyst for aziridination of olefins using Chloramine-T.

[reaction: see text] Pyridinium hydrobromide perbromide (Py x HBr3) catalyzes effectively the aziridination of electron-deficient as well as electron-rich olefins using Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source to afford the corresponding aziridines in moderate to good yields.

Fabric softeners and softness perception.

In order to evaluate the efficiency of various commercial chemical fabric softeners, a technique of obtaining subjective assessment known as 'magnitude estimation' was used to estimate the fabric softness. Particular emphasis was given to subjective scaling and limits of human perception. Comparison between softness and compression (a physical measure) was demonstrated.

Prevalence of intestinal parasites among food handlers in Al-Medinah.

Fecal specimens from 13.216 food handlers (male) adults, representing 21 different nationalities, were analyzed for the presence of intestinal parasites at King Abdul Azeez Hospital, Al-Medinah. Approximately 14% of these individuals harbored potentially pathogenic parasites, the most common organism being Giardia lamblia (33%), followed by Entamoeba histolytica (23%), Trichuris trichiura (12.3%), Ascaris lumbricoides (11.8%) and others. The highest incidence of parasite load was found in Sri Lankans (40.7%). Although G. lamblia and E. histolytica were found in almost all the nationalities, preponderance of metazoan parasites with complicated life cycles occurred in individuals from tropical countries where optimal conditions of temperature and humidity are favorable for the survival and development of these organisms.

A comparison of bacterial resistance to antimicrobials in Riyadh, Medina, and Oklahoma City.

Many bacteria are known to develop resistance to anti-microbial agents following their clinical use. The resistance pattern varies from one geographic location to another depending upon the patient population and local history of antibiotic use. The bacterial resistance to commonly used antimicrobial agents in Oklahoma City was found to be different from two cities in Saudi Arabia, especially amongst Gram-negative bacilli. A total of 13,575 fresh clinical isolates from the Veterans Administration Medical Center (VAMC), Oklahoma City, Oklahoma; the King Faisal Specialist Hospital and Research Centre (KFSH), Riyadh; and the King Fahad Hospital (KFH), Medina, Saudi Arabia; were used. There were 6,270 isolates of Enterobacteriaceae, 2,799 pseudomonads and Acinetobacter, and 4,506 Gram positive strains of staphylococcus bacteria. Gram-negative bacteria from KFH were considerably more resistant to ampicillin, gentamicin, and trimethoprim-sulfamethoxazole than at KFSH and VAMC. On the other hand, Staphylococcus aureus isolated from VAMC exhibited a significantly higher degree of resistance to oxacillin and trimethoprim-sulfamethoxazole than those at KFSH and KFH.

Postsynaptic supersensitivity in schizophrenia.

In the context of the dopamine hypothesis of schizophrenia, the authors examined postsynaptic dopamine (DA) receptor sensitivity in schizophrenic patients by means of a neuroendocrine strategy using the DA receptor agonist apomorphine and growth hormone (GH) release as the measurable postsynaptic event. The activity of platelet adenylate cyclase, an enzyme intimately associated with catecholamine receptor activity, was also studied following stimulation by prostaglandin E1 (PGE1). Patients diagnosed as having acute schizophrenia had significantly higher GH responses and adenylate cyclase activity than normal control subjects and patients diagnosed as having chronic schizophrenia. Chronic schizophrenic patients with and without tardive dyskinesia showed GH responses slightly lower than but not significantly different from those of control groups.