Biomedical subjects
Publications and source records attributed to M Hostettler.
Anti-wurtzite and wurtzite are shown to be the same crystal structure despite the claims of a recent paper describing the crystal structure of the mineral rambergite, Mn(1-x)Fe(x)S, x approximately 0.05. The anti-wurtzite/wurtzite confusion is used as an illustration to help clarify the correct general approach to take in the treatment and presentation of achiral non-centrosymmetric crystal structures.
The 1,10-decanedioic acid-1,3,5,7-tetraazatricyclo[3.3.1.1(3,7)]decane (1/1) system, C(10)H(18)O(4).C(6)H(12)N(4), was studied at 215 (2) K. Its analysis provides important information with regard to the long-standing acid-carboxylate controversy in the urotropine-alkanedioic acid system. In the present structure, all the chain end-groups display a clear acid character. The asymmetric unit of this commensurate modulated phase contains two molecules of diacid as well as two molecules of urotropine. Furthermore, the chain packing suggests a possible order parameter for the lock-in transition.
The title compound, C(6)H(12)N(4).C(9)H(16)O(4), undergoes several thermotropic phase transitions. The crystalline structure is layered, with sheets of azelaic acid linked to sheets of hexamethylenetetramine by hydrogen bonds. In the room-temperature phase, the azelaic acid molecules are disordered. By lowering the temperature, this disorder partially disappears. The ordering is clearly observed in reciprocal space where on the rods of diffuse scattering, present in the room-temperature phase, a series of superstructure reflections emerges. This phase transition leads to twin-lattice quasi-symmetry (TLQS) twinning. The structure of this twinned phase is explored in this paper. There are two orientational domains linked by a mirror plane which relates disordered orientations of the acid molecules above the phase transition. A single domain has space group P2_1/c. The structure has been solved and refined on the complete set of data to R(1) = 0.0469. The chains remain partially disordered, showing two acid groups with unequal population: the major form corresponding to a carboxylic acid and the minor to a carboxylate. The ordering of the structure, when going through the phase transition, is interpreted in terms of stabilization by C-H.O hydrogen bonding. A least-squares estimator of the twinning volume ratio is developed that gives an expression for the twinning ratio in terms of the intensities of nonoverlapping reflections. The twinning ratio obtained in the structure refinement compares very well with that obtained from this estimator.
The water-insoluble carob fraction (fraction insoluble caroube, FIC, Nestlé) has been successfully used in the treatment of infantile diarrhoea. To investigate the efficacy and toxicity of FIC (1970 mg to be taken every 2 hours over a 48-hour period except during sleeping time) in the treatment of travellers' diarrhoea in adults, a double-blind, computer randomized, placebo-controlled study was conducted. Of the 755 volunteers recruited at the Zurich University Vaccination Centre, 628 (83.5%) returned their questionnaires. Among them, 164 (27.7%) had diarrhoea, but only 69 (42%) used the trial medication correctly; the others were rated non-complaint. No significant difference in efficacy (p = 0.12) or adverse effects were observed in the two study groups. In conclusion, FIC, although showed a positive trend, was not efficacious.
The surgical treatment of herniated cervical discs is more frequent than it was 20 years ago, great progress having been made in diagnosis and especially in surgical techniques. In particular, the anterior access route should be mentioned here. Nowadays over 90% of patients can be freed from radicular pain by an operation. In the present review, problems of clinical symptomatology and surgical treatment have been studied in 51 patients, who all underwent surgery using the classic Cloward technique. The results of the classic Cloward technique, as far as we can judge today, are comparable with those of anterior discectomy without interbody fusion. However, the indications of the two operations are somewhat different.