Histamine receptors in the bronchial musculature and vasculature of the dog

Participation of histamine H1- and H2-receptors in the bronchial musculature and vasculature of the dog was investigated by using the method for evaluating airway responses. A peristaltic pump and a Starling pneumatic resistance were used for a constant pressure perfusion. Dogs given 0.1 - 10 micrograms histamine by a close intraarterial injection showed increases in ventilation overflow (bronchoconstriction) and in blood flow (bronchial vasodilatation) in a dose-dependent manner. The bronchoconstriction produced by histamine was antagonized strongly by chlorpheniramine, a H1-receptor antagonist, but not modified by cimetidine, a H2-receptor antagonist. The bronchial vasodilation produced by histamine was antagonized by both chlorpheniramine and cimetidine. These results suggest that histamine evokes bronchoconstriction through H1-receptors and bronchial vasodilatation through H1- and H2-receptors.     

Far infrared frequency synthesis with stabilized CO2lasers: Accurate measurements of the water vapor and methyl alcohol laser frequencies

A far infrared (FIR) frequency synthesis technique using saturated-absorption stabilized CO2lasers and a point-contact diode has been used to measure frequencies of a number of strong CW H2O, D2O, and CH3OH laser lines. The first frequency measurements of the 79-μm H2O, the 73- and 108-μm D2O, and 11 CO2-pumped CW¹²CH2¹⁶OH laser lines are reported. This measurement is the first demonstration of the general usefulness of CO2lasers for accurate synthesis of FIR frequencies.     

Effect of dietary n−3 polyunsaturated fatty acids on cholesterol synthesis and degradation in rats of different ages

Male Sprague-Dawley rats four weeks or eight months of age were fed purified diets containing 10% fat, either as a blend of safflower oil and palm olein (polyunsaturated fatty acids, PUFA, 34%), a blend of linseed oil and palm olein (PUFA, 33%) or sardine oil (PUFA, 33%) for four weeks. In other trials, sterol contents were made equivalent by supplementing cholesterol to a blend of corn oil and palm olein (PUFA, 30%) or phytosterol to sardine oil (PUFA, 30%). Fish oil was hypolipidemic in rats of different ages, but it tended to increase liver cholesterol in adult animals and this was not improved by the addition of phytosterol. The age-dependent increase in liver cholesterol was not duplicated in rats fed a vegetable fat blend supplemented with cholesterol. At both ages, liver 3-hydroxy-3-methylglutaryl coenzyme A reductase activity was lower in the sardine oil than in the other groups. There were no significant age- or diet-related differences in the activity of liver cholesterol 7α-hydroxylase. Fecal steroid excretion was comparable in age-matched rats fed diets supplemented either with cholesterol or phystosterol. Sardine oil reduced the Δ6-desaturase activity markedly as compared with linseed oil, and age-dependent reduction of the desaturase activity was observed in all dietary groups examined. Thus, the results showed a specific effect of fish oil on lipid metabolism.     

CCD linear image sensor with buried overflow drain structure

A CCD linear image sensor with buried overflow drain structure has been developed. Since the overflow drain, i.e. a reverse biased n-region buried under photosites arrayed in p-layer, makes an effective sink of excess electrons, imaging characteristics such as uniformity of photosensitivity, spectral response, resolution, and antiblooming, are highly improved.     

Preparation of amorphous Si3N4-C plate by chemical vapour deposition

Chemical vapour deposition of a Si-N-C system has been studied by using SiCl₄, NH₃, H₂ and C₃H₈ as source gases at deposition temperatures (T _dep) of 1100 to 1600° C, and total gas pressures (P _tot) of 30 to 100 torr. To control the amount of carbon in these deposits the propane gas flow rate [FR(C₃H₈)] was varied from 0 to 200 cm³ min^–1. Homogeneous plate-like amorphous deposits were successfully prepared atT _dep=1100 to 1300° C,P _tot=30 to 70 torr andFR(C₃H₈)=25 to 100 cm³ min^–1. The deposits were composed of amorphous silicon nitride and carbon and the carbon content increased up to 10 wt% with increasingFR(C₃H₈). The surfaces of the deposits had a pebble-like structure.     

Structural study of β‐SiC(001) films on Si(001) by laser chemical vapor deposition

β‐SiC thin films have been epitaxially grown on Si(001) substrates by laser chemical vapor deposition. The epitaxial relationship was β‐SiC(001){111}//Si(001){111}, and multiple twins {111} planes were identified. The maximum deposition rate was 23.6 μm/h, which is 5‐200 times higher than that of conventional chemical vapor deposition methods. The density of twins increased with increasing β‐SiC thickness. The cross section of the films exhibited a columnar structure, containing twins at {111} planes that were tilted 15.8° to the surface of substrate. The growth mechanism of the films was discussed.     

Nitrogen budgets and environmental capacity in farm systems in a large-scale karst region, southern China

Field surplus nitrogen (N) and farm disposal N are major sources of water pollution in farming systems. These sources are estimated from N budgets in field and whole farms, which are associated with the production and consumption of food. This study was conducted to evaluate these two pollution sources in the steep mountainous karst region of Quibainong, Guangxi Province, southern China. The region is, characterized as an area of upland farms, due to the shallow soils and rapid water drainage through cracks in the limestone. Although field surplus N in 1960 was only 4.1 kg N ha^–1, current field surplus N ranged from 10.1 to 463 kg N ha^–1, with values above 50 kg N ha^–1 in farms along roads and less than 40 kg N ha^–1 in the farms away from roads. The results obtained in near-road farms were similar to those in a previous study of N budgets in China. There was a significant positive correlation between the field surplus N and N application rate, including when the previous data were incorporated. The proportion of manure to total N application decreased with increase of N application. Chemical fertilizer was applied in greater quantity in economically rich farms. Therefore, the increase of field surplus N in Quibainong may be caused by economic improvement. Although livestock and human excreta were stocked in manure barns, unused excreta N increased with the increase of N excreted. The unused excreta N also increased with the decrease of feed self-sufficiency, but was not related to N application rate. These facts indicate that livestock husbandry in Quibainong is related to economic status of farms, but independently of crop production.The N application rate of more than 160 kg N ha^–1 increased field surplus N to an extent greater than crop uptake N, and a N application rate of more than 185 kg N ha^–1 increased the potential nitrate-N concentration to more than 10 mg L^–1. Therefore, 160–185 kg N ha^–1 is suggested to be the environmental capacity to sustain optimal N cycling in Quibainong. The average value of excreta N produced on near-road farms in Quibainong was 171 kg N ha^–1. If excreta N was used evenly for crop cultivation without chemical fertilizer in whole fields, the optimal N cycling would be maintained.The survey conducted here using a questionnaire was effective in evaluating all kind of N flows in the farming systems.     

Evaluation of Lead Zirconate–Titanate Ceramic Target for Sputter Deposition of Films for Use in Ferroelectric Capacitors

A high-density 3 in. diameter (Pb,La)(Zr,Ti)O3 [PLZT] ceramic target containing 20% excess PbO was sputtered by radio-frequency magnetron sputtering to deposit films containing excess Pb and evaluated with respect to target stability for use in the mass production of ferroelectric memories on Si wafers. The results indicated that PLZT film deposition rate increased with power but the excess PbO content correspondingly decreased. The Pb loss in the films was attributed to secondary preferential sputtering of film substrate in the plasma. Regardless of this difference, excess PbO containing 12 in. diameter PLZT ceramic targets were evaluated in a commercial sputtering system over a period of 7 months and the film Pb content was stable within ±1%.     

Trickle-Bed Oxidation Reactors

For reactions necesitating a solid catalyst and which invoive both reisuvely volatile and nonvclarile reactants, three-phase reactirs are required. Equipment used to achieve intimate contacting of the three phases has been procominantly in the form of slurry reactors, analogous to the stirred-tank homogenous system, or fixed-bed reactors in which the two fluid phases flow through a stationary bed of catalyst particles. Trickle-bed reactors are a type ofthe second classification in which both gas and liquid flow downward through the catalyst bed. Such systems avoid the disadvantage of separating small catalyst particles from the fluid product streams associated with slurry reactors, and also avoid the limitation of flow rates uncountered with upflow or countercurrent flow through fixed beds.     

Histopathological aspects of dural arteriovenous fistulas in the transverse-sigmoid sinus region in nine patients

OBJECTIVE: In recent years, dural arteriovenous fistulas (DAVFs) have been primarily thought to be acquired lesions, formed after sinus thrombosis. The pathogenesis of DAVF, however, is still controversial. We have studied histopathological aspects of DAVFs in resected specimens obtained from nine patients, to obtain clues to the pathogenesis of DAVFs. METHODS: Histological comparison was made among nine DAVF cases and five control cases without venous sinus disease. In addition, the relationship between the clinical course and histological aspects was investigated. RESULTS: The essential abnormality found was a connection between the dural arteries and the dural veins within the venous sinus wall, through small vessels averaging approximately 30 microns in diameter. By using several staining methods, we confirmed that the vessels were part of the venous system; we named these dilated venules "crack-like vessels." CONCLUSIONS: The development of abnormal communications between dural arteries and dural veins (crack-like vessels) is regarded as the essential part of the pathogenesis of DAVFs, and sinus thrombus is not thought to be an essential lesion of DAVFs. It might be postulated that sinus hypertension caused by stenocclusive disease of the venous sinuses triggers the development of fistulous connections between arteries and veins in the dural wall, which may result in increasingly dilated venules and the formation of DAVFs.