PubMed · 3204574
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P Grout, D Williams. 1988. Inter-practice visiting.. https://pubmed.ncbi.nlm.nih.gov/3204574/
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Conditions that would permit the complete structure determination of spherical viruses that have high internal symmetry were examined starting only from an initial spherical shell model. Problems were considered that might arise due to the following. 1. Creation of centric phases due to the simple shell model and its position in the unit cell. The centric symmetry can generally be broken on averaging an initial electron density map based on observed structure amplitudes, provided that the internal molecular symmetry is sufficiently non-parallel to the crystallographic symmetry. 2. Choice of the average model shell radius. Some incorrect radii led to the Babinet opposite solution (electron density is negative instead of positive). Phases derived from other models with incorrect radii failed to converge to the correct solution. 3. Error in structure amplitude measurements. 4. Lack of a complete data set. 5. Error in positioning the initial spherical-shell model within the crystal unit cell. It was found that an error of 1.6 A caused noticeable phasing error at a resolution greater than 20 A.
A computer-controlled radiation therapy technique is demonstrated which uses multiple concurrent boost fields to modify the beam profile of a conventional treatment beam. A principal field, identical to that of a corresponding conventional treatment plan, delivers the major component of the prescribed dose. Dose increments given from boost fields placed within this principal field compensate for variations in patient anatomy, for variations in target volume shape, and/or for imperfect beam characteristics, such as excessive off-axis dose or inadequate beam wedge angle. This concurrent boost field technique is demonstrated for several treatment sites. It produces significant improvement in uniformity of dose delivered to the target compared to conventional treatment. Implementation of these treatments requires a computer-controlled linear accelerator with independently-movable collimator jaws, an automatic beam set-up procedure, and a patient prescription database. Since all fields are delivered under computer control, concurrent boost technique treatment times are not much longer than those of conventional treatments.
Infants with the severe variant of glucose-6-phosphate dehydrogenase (G6PD) deficiency may develop hyperbilirubinaemia sufficiently severe to cause kernicterus and death, acute haemolysis on exposure to oxidant stress, congenital non-spherocytic haemolytic anaemia and, rarely, increased susceptibility to bacterial infection. In spite of these potential problems, G6PD deficiency is often not included among screening programmes for inherited disorders. In a comprehensive screening and educational programme, we tested around 34,000 infants for G6PD deficiency. Of the total group, 18.4% (24.5% boys and 11.8% girls) were deficient. Forty-two of the 6246 (0.67%) G6PD-deficient infants required exchange transfusion. None of them developed kernicterus. By contrast, of 4755 infants who had not been screened because they were born at home, three developed kernicterus. In addition, four G6PD-deficient infants had developed kernicterus in the 20-month period prior to the screening programme. None of the hyperbilirubinaemic infants had blood group incompatibility or any other identifiable cause of hyperbilirubinaemia. To avoid this disastrous result, we believe that neonatal screening for G6PD deficiency, together with a comprehensive education programme, is advisable in those parts of the world where the severe variant of G6PD deficiency is prevalent.