Efficient planar convex hull algorithm

A new algorithm for computing the convex hull of a planar set of points is presented. The method of determining the set of suitable candidates is compared with previous algorithms. The algorithm is also compared with other algorithms in terms of running time and storage requirements, and experiments indicate that it is at least as good in terms of space and generally better in terms of running time.     

Results of the treatment of bladder tumors infiltrating the muscle

The results of PUVA treatment for severe alopecia areata (AA) were reviewed in 102 patients. Fifty-three per cent had greater than 90% regrowth of hair. Although these results appear to be encouraging, they differ little from what would be expected with no treatment. We consider that PUVA is not an effective treatment for AA.     

The initiation of a calcium signal in Xenopus oocytes

Clinical and radiographic healing observations were categorized into four patterns: rapid, typical, delayed, and adverse. While considerable overlap of characteristics was noted between the categories, singular factors or combinations of factors enabled pattern identification. The factor primarily associated with the rapid healing pattern was the appearance of bone in the former defect adjacent to the membrane at removal. In contrast, the adverse healing pattern depicted surface necrosis or loss of tissue height at membrane removal. One hundred random sites were evaluated, revealing 13% rapid healing patterns, 76% typical healing patterns, 8% delayed healing patterns, and 3% adverse healing patterns. With favorable patient compliance with oral hygiene and follow-up care, the rapid and typical healing patterns became clinically successful cases. The level of clinical success varied with the delayed healing pattern; the adverse pattern failed to achieve the therapeutic objective.     

The diagnostic value of serum lysozyme activity in inflammatory bowel disease

The inferior alveolar nerve was cut or the vessels entering the mandibular canal were damaged in 39 guinea pigs at 10 days of age. Possible changes in the incisors were recorded during a 100-day observation period whereafter the animals were killed and the skulls freed of soft tissues; at this time, 35 skulls were found suitable for further examination. The changes in the mandibular incisors on the operated side became observable 30-40 days post-operatively as discolourization, a 'trauma line' around the tooth, narrowing of the tooth or total loss of it's visible part. In the guinea pigs with the nerve cut (group A), such signs of maldevelopment were seen in 5 out of 19 animals, whereas the corresponding figure for the animals with the damaged vessels (group B) was 14/16. All incisors in group A and 13 out of 14 in group B recovered from the state of maldevelopment; one animal in group B showed complete loss of the incisor. The molar region was examined only from the cleaned skulls. In group A, the first molar was deformed in two animals; in group B, seven animals displayed either maldevelopment of the first molar or the first and second molar or complete loss of the first molar. No malformation of the third molar was observed. With two exceptions, the deformation or loss of molars occurred in combination with incisor maldevelopment. The malformations were considered to result from a disturbed blood supply. In group A, the dental changes may perhaps be ascribed to a short-term interference with the blood supply during the operation. The variable results in group B seem to imply that the mandibular teeth receive at least part of their blood supply from vessels besides those entering the mandibular canal. The innervation appears to have a subordinate role in the restoring of the morphology of continuously erupting teeth.