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Thin film imaging offers the possibility of extending 248 nm lithography to sub 150 nm resolution. We have been working on a 248 nm bilayer imaging scheme which utilizes a thin Si-containing resist on top of a thick, planarizing underlayer. The image is developed in the top layer and transferred to the underlayer via O2-based plasma etching. This article focuses on three aspects of the critical transfer etch process: etch resistance of the imaging resist, profile control and resist roughening. The imaging resist thickness loss is very fast during the first few seconds of the etch after which the rate diminishes. The relative importance of three phenomena that can explain this nonlinear behavior: oxidation of silicon, deprotection of resist moieties, and plasma etching of resist, are discussed. Fourier transform infrared studies on imaging resist films indicate minimal deprotection-related film thickness losses. X-ray photoelectron spectroscopy analyses of etched films indicate that the extent of surface oxidation increases initially and then becomes constant. Thus, the etching of this category of resists can be described as a combination of the oxidation of the silicon species and sputtering of the oxide-like layer formed. Post-transfer etch profiles using an O2 plasma are shown, and methods to reduce imaging resist faceting and thickness loss either by modifying the imaging layer silicon content or by using passivating plasma chemistries are discussed. The effect of different etching chemistries and processing conditions on imaging layer roughening and striation formation on underlayer sidewalls are explained with the aid of scanning electron microscopy micrographs and atomic force microscopy images of etched feature sidewalls. It is shown that the SO2–O2 etch significantly reduces the sidewall roughness from the postlithograpy values. The ∼3.5 nm rms sidewall roughness observed postetch is comparable to postdeveloped roughness values measured for mature single layer resists. The printing of 125 nm line/space patterns and 150 nm trench features with 10:1 aspect ratios in the underlayer is also demonstrated.

The aim of the present study was to determine whether dietary peptide concentration had an effect on endogenous ileal amino acid flow in the growing pig. Eight 33 kg live weight entire male pigs had post-valve T-caecum (PVTC) cannulas surgically implanted for the collection of ileal digesta. The pigs were fed twice daily at 100 g/kg metabolic body weight per d and were given diets containing enzyme-hydrolysed casein (EHC) at 0, 50, 100 and 200 g/kg in a Latin-square design. A basal casein-based diet was fed to the pigs for 6 d periods between receiving the experimental diets. The pigs received the experimental diets for 8 d periods, with continuous collection of digesta for 24 h on each of the fifth and eighth days. The endogenous ileal amino acid flows were determined with reference to recovery of the marker, Cr, directly for pigs receiving the protein-free diet or after centrifugation and ultrafiltration (10,000 Da molecular mass cut-off) for pigs on the EHC-based diets. Mean endogenous ileal N flows were 1753, 1948, 2851 and 5743 micrograms/g DM intake when the pigs received diets containing 0, 50, 100 and 200 g EHC/kg respectively. There was a significant (P0.05) effect of dietary peptide concentration on the endogenous ileal flows of N and all of the amino acids, with an increase in endogenous ileal amino flow with increasing dietary EHC concentration.

The effect of selective vagotomy of the abomasum, pylorus, duodenum and liver on insulin release during the cephalic phase of digestion was investigated in wethers and lactating ewes. Electrical stimulation of the cervical vagus nerves was carried out to test the completeness of the vagotomies performed. In experiment 1, using wethers, the abomasal, pyloric and duodenal branches (ADV; n = 7) or the hepatic, abomasal, pyloric and duodenal branches (HADV; n = 10) of the ventral and/or dorsal vagus nerves were cut; a third group of wethers underwent sham-operation (SO; n = 8). In experiment 2, vagotomy (ADV; n = 5) or sham-operations (SO; n = 5) were carried out in lactating ewes. Jugular blood was drawn before and after presentation of food for glucose and insulin determination (experiments 1 and 2) or before, during and after the electrical stimulation of the peripheral ends of the cut cervical vagus nerves in randomly selected lactating ewes (experiment 3: ADV = 3, SO = 3) and wethers (experiment 4: ADV = 4, HADV = 4, SO = 4), for determination of insulin only. Presentation of food caused an immediate and significant (P0.05) rise in plasma insulin levels in SO animals compared with ADV or HADV wethers (experiment 1) or ADV ewes (experiment 2) without any significant change in blood glucose concentrations. In comparison with the SO group the baseline-corrected areas under the insulin response curve were significantly (P0.05) smaller for the respective vagotomized groups for periods 1-2, 2-4 and 4-6 min (experiment 1) and 1-2 and 2-4 min (experiment 2) after presentation of food. Total area under the response curve for 10 min was significantly (P0.05) lower (experiment 1) and tended (P0.10) to be lower (experiment 2) for the vagotomized groups compared with that of the control groups. Direct electrical stimulation of the cervical vagus nerves raised plasma insulin concentrations to significantly (P0.05) higher levels in the SO ewes but not in the ADV ewes (experiment 3). It was also evident that in experiment 1, HADV did not have any additive effect over that achieved by ADV alone. These results indicate that the vagal innervation of the gut mediates insulin release during the cephalic phase of feeding in sheep. It is concluded that insulin secretion from the pancreatic -cells in response to either food-related reflex activation of the vagal nuclei in the hypothalamus or direct cervical vagus nerve stimulation is mediated through the vagal efferent fibres carried in the abomasal, pyloric and duodenal branches of the vagus nerves in sheep.

Yersinia enterocolitica enteritis in newborn, colostrum-deprived piglets fed a human milk formula caused a reduced milk intake and decreased gain in weight but not length of the body. In infected piglets, the weight of the liver was less than in controls but other abdominal organs were unaffected. The weight of the caecum and small intestinal muscle were greater, but the length and weight of the small intestine and colon were not different. In infected piglets, the RNA concentration of the small intestinal mucosa was elevated whereas the concentrations of DNA and protein were unchanged, and total lactase activity was reduced. After antibiotic therapy, the liver weight was greater and the body weight increased at the same rate as the controls but was still lower at 14 days. The body weight of the control piglets increased linearly over the 14 days after birth. The stomach, pancreas and spleen grew more rapidly, but the liver more slowly, than the body as a whole but the kidneys had a minimum relative weight at 5 days. The total lactase activity and protein and RNA concentrations of the small intestinal mucosa decreased with age, the RNA to a greater extent than the protein.

Unitary impulse activity from tension receptors in the abomasal antrum in sheep anaesthetized with chloralose was studied with concurrent measurements of isometric tension in the antral wall, intraluminal pressures and electromyography (EMG). Rhythmical background activity had a close correlation with intraluminal pressure changes and usually a close correlation with local increases in EMG activity and isometric tension. Impulse frequencies increased, but were not sustained, following changes from isotonic to isometric conditions. Tension receptors were excited by transmural compression, by antral distension and by local intra-arterial injections of acetylcholine (2.5-25 micrograms), pentagastrin (10-20 micrograms), 5-hydroxytryptamine (1-20 micrograms), adrenaline (10 micrograms) cholecystokinin-8 (1-5 micrograms) or bradykinin (0.5-20 micrograms), and by systemic injections of bethanecol (5-1000 micrograms). Local intra-arterial perfusions of atropine (50 micrograms) and hexamethonium (100 micrograms) did not abolish spontaneous antral movements or affect the enhanced impulse activity evoked by acetylcholine or 5-hydroxytryptamine. Most antral tension receptors were excited by increases in antral tension or passive distension; they therefore functioned 'in series' with the muscularis externa. The discharges of three tension receptors were 'off-loaded' early during the contraction evoked by local injections of pentagastrin (10-20 micrograms).

Growth and morphological changes in the small and the large intestine of piglets were examined during the first three days after birth. There was a 72% increase in small intestinal weight, virtually all of which occurred during the first day and was due primarily to a 115% increase in the weight of the mucosa. Associated with the tissue weight gain there was a 24% increase in small intestinal length, a 15% increase in small intestinal diameter, a 33-90% increase in villus height and a 14-51% increase in villus diameter, during the first day. The cellular population in the small intestinal mucosa, as indicated by its DNA content, increased progressively with age, and at three days had increased by 84-154%. The percentage increase in mucosal DNA content was highest in the duodenum, intermediate in the jejunum and lowest in the ileum. Histological features and tissue protein contents revealed a transient epithelial cellular swelling related to intracellular accumulation of protein on the first day. Protein accumulation was evident in the jejunum and ileum but not in the duodenum. The positions of the nuclei in the epithelial cells suggested that on the first day protein absorption was at a more advanced stage in the jejunum and the proximal ileum than in the distal ileum. Large intestinal weight increased by 33% during the first day and had doubled by the third day, and this weight gain was due to both mucosal and non-mucosal tissue growth. Villus-like structures were observed in the caecum and the proximal colon in piglets at birth and one day after birth but not in piglets three days after birth. It is speculated that such villus-like structures may have a functional significance during the transition to complete dependence on oral nutrition in newborns.

Haemodynamic comparison of three vasodilation regimens [intravenous (i.v.) hydralazine and isosorbide dinitrate (ISDN) combined, i.v. doxazosin, and i.v. enalaprilat] was undertaken in 36 patients with acute left ventricular (LV) failure due to recent myocardial infarction. Each regimen achieved similar reductions in pulmonary artery occluded pressure (PAOP, preload) and systemic arterial pressures (afterload), with increased cardiac and stroke volume (SV) indexes (p less than 0.01). Only the hydralazine and isosorbide combination induced resting tachycardia. Balanced vasodilatation after selective alpha-adrenoceptor blockade (doxazosin) and angiotensin-converting enzyme (ACE) inhibition (enalaprilat) without increase in heart rate (HR) suggests that these therapies may have definite haemodynamic advantages over the hydralazine/ISDN combination.

Growth and morphological changes in the stomach of newborn pigs were examined during the first 3 days after birth. The stomach grew disproportionately faster than the body as a whole during this period. The growth was due to hyperplasia and hypertrophy during the first day and mainly to hyperplasia thereafter as gastric DNA content increased progressively after birth, and the protein:DNA and RNA:DNA ratios increased only on the first day. Histological and morphometric analyses revealed that the growth was more pronounced in the gastric body region than in the cardiac and pyloric regions, and more pronounced in the mucosal layer than in other layers. The percentage of mucosal volume occupied by parietal cells (volume density) and the number of parietal cells per unit volume of gastric mucosa (numerical density) increased significantly 3 days after birth in the cardiac and body regions, but not in the pyloric region, of the stomach. The observed morphological changes coincide with the known pattern of functional maturation during the immediate postnatal period. It is suggested that a high level of circulating gastrin and oral ingestion of milk-derived growth factors in the newborn pig contribute to these changes.

Coagulase negative staphylococci are the principal cause of prosthetic valve endocarditis but are a rare cause of native valve infections. However, the incidence of native valve endocarditis is increasing. Staphylococcus capitis is a coagulase negative staphylococcus with the capacity to cause endocarditis on native heart valves. Two cases of native valve endocarditis caused by S capitis are presented; both in patients with aortic valve disease. The patients were cured with prolonged intravenous vancomycin and rifampicin and did not need surgery during the acute phase of the illness. Five of the six previously described cases of endocarditis caused by this organism occurred on native valves and responded to medical treatment alone. Keywords: Staphylococcus capitis; endocarditis; valvar disease; coagulase negative staphylococci

The principal phenolic constituents were isolated from the exudate of the glandular trichomes of TURRICULA PARRYI, a California shrub that causes severe contact dermatitis. The phenolic constituents consist of a complex mixture of methoxylated flavones and derivatives of both farnesylhydroquinone and 3-farnesyl- P-hydroxybenzoic acid in which the C-7 methyl of farnesyl is replaced by hydroxymethyl, formyl and carboxyl groups. Elicitors of allergic contact dermatitis were identified with guinea pigs sensitized to the crude exudate. The principal agents of dermatitis were the farnesyihydroquinone derivatives 3 and 6.

Extracts of sheep intestine prepared to contain secretin were readily obtained, reacted with antibodies raised to pure natural porcine secretin, were potent stimulants of pancreatic exocrine secretion of the anaesthetised rat and failed to contract sheep gall bladder in vitro. In contrast extracts prepared to contain cholecystokinin (CCK) caused contraction of sheep gall bladder in vitro but were more difficult to obtain than those of secretin due to a contaminant green pigment. The experiments provide biological and immunological evidence for the existence of secretin in sheep intestine. The demonstration of CCK activity on sheep gall bladder by separate extracts is indicative of the presence of CCK in the sheep but this awaits confirmation by immunological means.

When solutions of zinc sulphate are administered to sheep by drenching gun (100 and 50 mg Zn/kg/day) the toxicity of zinc is markedly enhanced. Using a drenching gun method, severe lesions of the abomasum are encountered, serum and organ zinc levels are increased, pancreatic damage is severe, and even death may occur using doses which are apparently non-toxic when delivered by intraruminal intubation. It is suggested that the stimulation of the reticular groove by zinc is responsible for the exacerbation of toxicity when zinc sulphate is delivered by drenching gun.

Larvae of Pseudoplusia includens (Walker) reared on the resistant plant introduction (PI) 227687 exhibited reduced growth and high mortality relative to those reared on the susceptible cultivar ‘Davis.’ These effects were most pronounced in the last instar and resulted from an acute action on this instar. The plant genotype consumed during instars one through four had no effect on the maximum larval weight attained, pupal weight, or total mortality during larval development, but did affect the duration of larval development. Measurement of food consumption and utilization by larvae of P. includens fed on PI 227687 or ‘Davis’ foliage indicated that reduced growth on PI 227687 was primarily due to feeding deterrence or the lack of feeding stimulation. A lower efficiency of conversion of digested food to body tissue, not attributable to reduced consumption, also contributed to reduced P. includens growth rate on PI 227687.

The effect of zinc on the destination of fluids administered by drenching gun to sheep was determined by a crystal violet dye-indicator-slaughter method. Zinc in drench solutions produced more direct passage of drench to the abomasum as indicated by increased dye staining of abomasal and omasal mucosa and abomasal contents. Stimulation of the reticular groove reflex is suggested. Increased concentrations of zinc increased the effect. The stimulatory effect was similar to that produced by copper salts.

Thin surface copper-nickel alloys were prepared by ion implantation at 90 keV. During the implantation of one pure element by the other the sputtered products were collected on catcher foils at different stages from the beginning of the implant through to the steady state configuration of the target surface. The collector foils and targets were analyzed to determine the behavior of the sputtering yields during implantation and for the change in surface composition at the selected fluence. The total sputtering yield for the target and the effective elemental sputtering yields for each component appear to be functions of the changing surface fractions, the self ion sputtering yield of the implanted species, and the elemental sputtering yield of the initial target species. A model relating these parameters is presented.

Radioimmunoassay of gastrin in gastrointestinal tissues of lambs and adult sheep showed highest concentrations (796 to 11,156 pmol g-1 mucosa) in the antral region of the abomasum. The next highest concentrations of gastrin were in the proximal duodenal mucosa (16 to 518 pmol g-1). Gastrin was undetectable or present in lower concentrations in caudal regions of the duodenum (less than 11 X 5 pmol g-1), the pancreas and in the body of the stomach. It is concluded that the distribution of gastrin secreting cells in sheep is similar to that in other animals.

The T-lymphocyte differentiation alloantigens, A.R.T.-1 and A.R.T.-2 were used to follow the functional development of these cells in the rat. Delayed hypersensitivity and lymphocytes cytotoxic for allogeneic tumor cells were present in adoptively transferred recipients by 3 wk postirradiation and fetal liver reconstitution. However, these animals did not regain appreciable GvH potential until 7.5 wk postreconstitution. Normal percentages of A.R.T-1 lymphocytes were observed at all times in the spleen and lymph nodes of these animals, whereas, below normal numbers of A.R.T-2 lymphocytes were observed up to 7.5 wk postreconstitution. Depletion experiments using specific anti-A.R.T. sera demonstrated that the proliferative response to PHA and the cytotoxic lymphocyte response to alloantigens were reduced after treatment with anti-A.R.T.-1, but not with anti-A.R.T.-2. In contrast, the GvH potential of lymph node cells was reduced by treatment with either anti-A.R.T.-1 or anti-A.R.T.-2 serum plus complement. The use of these A.R.T. alloantisera in the rat has greatly facilitated the establishment of differentiation patterns for functional T lymphocytes and has resulted in the association of specific functional T-cell subpopulations with characteristic surface alloantigens.

Earth based orbit determination for Mars orbiting spacecraft, comparing batch and sequential tracking filter data processing methods