Clinical picture of peptic ulceration diagnosed endoscopically

Clinical features and laboratory data are presented for 100 patients with benign gastric ulceration and 150 patients with duodenal ulceration confirmed endoscopically in a district general hospital unit. Abdominal pain was the commonest indication for endoscopy, but one third of examinations were performed for acute gastrointestinal haemorrhage. Although the patients were selected by referral for endoscopy their clinical presentation, age, and sex distribution were similar to those reported in previous general surveys. There were no clinical features which clearly distinguished gastric from duodenal ulceration. However, of those with gastric ulceration younger patients more often had distal ulcers and presented with pain, while elderly subjects tended to have high lesser curve involvement and presented with haemorrhage. Moreover, all females presenting with haemorrhage were aged over 50 years, while 6% of males bleeding from gastric ulceration and 40% of males bleeding from duodenal ulceration were under this age. Anaemia when present, except in two premenopausal females, indicated either a recent acute gastrointestinal haemorrhage or a coexistent second diagnosis.     

Kinetics and mechanisms of chemical reactions in nonequilibrium-plasma etching of silicon and silicon compounds

Plasma-chemical etching of silicon and silicon compounds is reviewed. It is shown that present data indicates that fluorine atoms and molecules are the main particles responsible for etching of silicon and that atomic fluorine is the main active particle for etching of silicon dioxide. Insufficient data exists to establish the contribution of charged and excited states to the etching of silicon and its compounds but oxygen atoms and molecules are seen to have a strong influence and fluorocarbon radicals can passivate the surface by forming polymer films.