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Notes: Neutron diffraction techniques have been used to study the antiferromagnetic form factor of Sr2CuO2Cl2, which has the body-centered-tetragonal (I4/mmm) K2NiF4-type structure (the same as that of tetragonal La2CuO4 but with the out-of-plane oxygens replaced by Cl and the La by Sr). The antiferromagnetic form factor was obtained at 15 K by measuring the integrated intensities of the ( (1)/(2) (1)/(2) 0), ( (1)/(2) (1)/(2) 2), ( (1)/(2) (1)/(2) 3), ( (3)/(2) (3)/(2) 0), ( (3)/(2) (3)/(2) 6), ( (3)/(2) (5)/(2) 1), ( (3)/(2) (3)/(2) 8), and ( (5)/(2) (5)/(2) 0) magnetic reflections of a single crystal of Sr2CuO2Cl2. The experimentally determined magnetic form factor is similar to that of La2CuO4. The experimental data were compared with the Cu2+ magnetic form factor and with the results of band theoretical calculations. We find that the fit to the experimental data is improved if one assumes a dipolar spin polarization on the in-plane oxygen ions.

Notes: Neutron-diffraction techniques have been used to study the antiferromagnetic form factor of a La2NiO4 single crystal at 15 K. The antiferromagnetic form factor was obtained by measuring the integrated intensities of 16 magnetic reflections. A plateau is clearly seen at low Q (up to 3 A(ring)−1) in the experimentally determined form factor, similar to those observed for La2CuO4 and Sr2CuO2Cl2. As in the case of these latter compounds, the fit of the experimental data by a Ni2+ ionic form factor is not satisfactory. The experimental data are compared with a recent spin-polarized band calculation and with a covalency model.

Notes: Neutron diffraction experiments have been performed in order to study the magnetic ordering of BaCuO2+x. In these measurements unpolarized neutrons and polarized neutrons with full polarization analysis have been utilized. From these measurements it has been determined that BaCuO2+x orders antiferromagnetically below TN=15.0±0.5 K with a magnetic propagating vector κ=[1 1 1]. This structure is commonly referred to as a [πππ] or a G structure. The Cu atoms in the Cu6 ring clusters, located at the (1/4, 1/4, 1/4) positions, order ferromagnetically within these clusters while the clusters themselves order antiferromagnetically. The ordered magnetic moment of each of these Cu atoms is 0.89±0.05 μB at T=4.2 K. No evidence of long-range magnetic ordering of the Cu atoms in the Cu18 clusters, located at the (0, 0, 0) and (1/2, 1/2, 1/2) positions, was found down to a temperature T=2.5 K. The work at Oak Ridge National Laboratory (ORNL) was sponsored by the Division of Materials Sciences, U.S. Department of Energy (DOE). ORNL is managed for the U.S. DOE by Martin Marietta Energy Systems, Inc., under Contract No. DE-AC05-84OR21400. Ames Laboratory is operated for the U.S. DOE under Contract No. W-7405-Eng-82. The work at Ames was supported by the Director for Energy Research, Office of Basic Energy Sciences.

Notes: A photoluminescence study of the effects of annealing on Si-doped (∼1016 cm−3) GaAs grown on (311)A-, (111)A-, (111)B-, and (100)-oriented substrates by molecular-beam epitaxy has been performed. The anneal temperatures were 873, 973, and 1098 K. All the anneals were of 24 h duration. Detailed assessment of the low-temperature photoluminescence spectra suggests that site switching (Si switching from Ga site to As site) only occurs in the n-type samples [(100) and (111)B samples] and not in the p-type ones [(111)A and (311)A samples].

Notes: Forty-eight children, aged between 2 and 10 years, admitted as day cases for otological surgery were allocated at random into two groups. The first group was anaesthetised using a standard facemask, and the second with a laryngeal mask airway. The laryngeal airway produced a satisfactory airway in all children, and was inserted on the first attempt in 67% of patients. Hypoxia was significantly less frequent in the laryngeal airway group (p 〈 0.05), and there were significantly fewer interruptions to surgery than in the facemask group (p〈 0.001). Patient safety, operating and anaesthetic conditions were all considered superior in the laryngeal airway group.

Notes: A novel grading method which utilises intra-cellular mucin content and tubular differentiation (the Goseki grade) has been applied to 181 gastric cancers removed in potentially curative resections, and compared to conventional tumour grading (well, moderate, poor differentiation) and the Lauren, Ming and WHO classifications. The Goseki grade is significantly related to patient survival and, unlike the existing approaches, remains so after allowing for tumour stage in multivariate analyses. Potential relationships between the Goseki grade, direct tumour spread, lymph node involvement and survival have been investigated. Prognosis is particularly related to mucin content; 55% of patients with mucin-rich tumours dying within 5 years compared to 29% of those with mucin-poor cancers. A smaller proportion of mucin-poor cancers show lymph node involvement (N1 and N2) than mucin-rich tumours (52%v. 73%) and a smaller proportion of cancers showing good tubular differentiation exhibit widespread lymph node involvement (N2) than tubule-poor cancers (11%v. 28%). However, these differences did not achieve statistical significance. When compared to the existing classification or grading methods, the Goseki grade was found to be highly significantly correlated with the WHO and Lauren classifications and to conventional grading, but not to the Ming classification. These inter-relations are largely dependent upon tubular differentiation. There was no relationship between Goseki grade and the lymphocytic response around the tumour margin. Inter-observer agreement on the WHO type and the Lauren, Ming and Goseki grading methods was tested on 70 randomly selected cases. Only moderate agreement was achieved with any of these approaches (pairwise kappa values ranging from 0.485–0.565), but when the two-category situation ‘mucin-rich’ versus ‘mucin-poor’ was examined a higher level of reproducibility was achieved (agreement = 81%; K= 0.605) indicating that pathologists can distinguish these prognostically important categories. It seems likely, therefore, that the strength of the association between tumour cell mucin content and survival will outweigh discrepancies introduced by observer variation.

Notes: The effect of duodenal ulcer healing on the acid secretory responses to modified sham feeding and maximal pentagastrin stimulation has been studied in 17 patients treated successfully with ranitidine (n= 9) and sucralfate (n= 8). Parietal cell sensitivity was calculated as the ratio of the modified sham feeding response to the peak pentagastrin response, expressed as a percentage. Ulcer healing after sucralfate therapy resulted in significant falls in modified sham feeding stimulated acid output (P 〈 0.02), from 9.4 (1.8–17.0) (median + range) to 3.7 (0.2–9.4) mmol/h; in peak acid output (P 〈 0.05) from 42.8 (23.0–61.4) to 27.7 (7.2–51.0)mmol/h; and in the parietal cell sensitivity (P 〈 0.05) from 19.2 (4.4–42.6) to 14.3 (2.8–19.7)%. No significant falls in any of these parameters were noted following ulcer healing with ranitidine. Duodenal ulcer healing with sucralfate results in decreased acid secretory responses to vagal and pentagastrin stimulation.

Notes: This paper reports a double-blind placebo-controlled trial of oral tobramycin in acute ulcerative colitis. Eighty-four patients with an acute relapse of ulcerative colitis were randomized to receive oral tobramycin or placebo for 1 week as an adjunct to steroid therapy. At endpoint, 31 of 42 (74%) in the tobramycin group achieved complete symptomatic remission compared with 18 of 42 (43%) in the placebo group (P= 0.008). The tobramycin group achieved better histological scores (P 〈 0.05) at endpoint. These findings show that treatment with oral tobramycin improves the short-term outcome of patients with ulcerative colitis in relapse.