scholarly journals Unusual hydrogen implanted gold with lattice contraction at increased hydrogen content

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Khac Thuan Nguyen ◽  
Van Hiep Vuong ◽  
The Nghia Nguyen ◽  
Trong Tinh Nguyen ◽  
Tomoyuki Yamamoto ◽  
...  

AbstractThe experimental evidence for the contraction of volume of gold implanted with hydrogen at low doses is presented. The contraction of lattice upon the addition of other elements is very rare and extraordinary in the solid-state, not only for gold but also for many other solids. To explain the underlying physics, the pure kinetic theory of absorption is not adequate and the detailed interaction of hydrogen in the lattice needs to be clarified. Our analysis points to the importance of the formation of hydride bonds in a dynamic manner and explains why these bonds become weak at higher doses, leading to the inverse process of volume expansion frequently seen in metallic hydrogen containers.

1989 ◽  
Vol 61 (03) ◽  
pp. 463-467 ◽  
Author(s):  
G M Smith

SummaryIn this study, 5-hydroxytryptamine (5-HT) caused a dose- dependent fall in the circulating platelet count suggesting that 5-HT receptors are activated in rat platelets to cause platelet adhesion and aggregation. When low doses of adenosine diphosphate (ADP) were simultaneously injected with 5-HT, there was a significant potentiation of the responses to ADR Ketanserin significantly reduced the potentiated responses. When higher doses of ADP were infused with bolus injections of 5-HT there was no potentiation and ketanserin did not reduce these responses. Ketanserin did not inhibit the collagen-induced fall in circulating platelet count, but did significantly increase the rate of return to the basal platelet count compared with control. 5-HT did not cause a fall in platelet count in guinea-pigs


1984 ◽  
Vol 102 (3) ◽  
pp. 381-386 ◽  
Author(s):  
R. Gross ◽  
P. Mialhe

ABSTRACT To elucidate the hypolipacidaemic effect of insulin in ducks, its action on the uptake of free fatty acids (FFA) by duck hepatocytes was determined. At low doses (10 mu./l) insulin stimulated FFA uptake. This effect was not observed with higher doses of insulin (20, 30 and 50 mu./l). Growth hormone at physiological concentrations and corticosterone (14·4 nmol/l) decreased basal activity, probably by reducing glucose metabolism and consequently α-glycerophosphate (α-GP) supply. Insulin was able to reverse the inhibition induced by GH and corticosterone on both FFA uptake and α-GP production. These results therefore suggest that the hypolipacidaemic effect of insulin may be partly mediated by its action on hepatic FFA uptake. J. Endocr. (1984) 102, 381–386


2018 ◽  
Vol 9 (24) ◽  
pp. 3379-3387 ◽  
Author(s):  
Monica Cîrcu ◽  
Claudiu Filip

13C/1H/2H ss-NMR on deuterated samples provide strong experimental evidence for the most probable monomer connectivity, π–π stacking, and the water dynamics in polydopamine.


1981 ◽  
Vol 36 (11-12) ◽  
pp. 1091-1092 ◽  
Author(s):  
T. Söylemez ◽  
W. Baumeister ◽  
L. M. Herbertz

Abstract For the transformation of glutamic acid into α-amino-butyric acid upon irradiation a decarboxylation mechanism involving the formation of CO2 has been proposed previously. Here we present further experimental evidence in favour of this mechanism. A dditionally the formation of CO as a decarboxylation product has been detected; a radical anion mechanism for its formation is proposed.


1979 ◽  
Vol 47 (1) ◽  
pp. 26-31 ◽  
Author(s):  
M. King ◽  
N. Viires

The effect of methacholine chloride (M) on tracheal mucus was investigated in three conscious tracheostomized dogs. Aerosols of M in concentrations of 2--32 mg/ml were delivered intratracheally for 1 min. Mucus was sampled with a cytology brush at 2 min postchallenge and at irregular intervals thereafter. The mechanical properties of each sample were determined in the magnetic microrheometer, and correlated with mucociliary transportability as assayed by the frog palate technique. With high doses of M, there was an increase in volume of secretion collected per unit time. The elastic modulus (G′) at 2 min postchallenge went up (to 1.5 x 2.3 x control for 16 and 32 mg/ml, respectively) then fell below control before returning to base line after 30 or 45 min. With low doses of M (2--8 mg/ml) the secretion rate was also above control, but only a decrease in G′ (to 0.54 x control) was observed. The decrease in G′ at low doses did not significantly alter the frog palate transport rate; however, the increase at higher doses did impede mucociliary transport.


1962 ◽  
Vol 202 (3) ◽  
pp. 429-436 ◽  
Author(s):  
Frank M. Byers ◽  
Paul H. Jordan ◽  
Thomas H. Maren

The gastric H+ secretory responses to i.v. HCl, NaHCO3, and acetazolamide were studied in Heidenhain-pouch dogs that had been stimulated to secrete by feeding. Acetazolamide in low doses (5 mg/kg) gave a 65% reduction in H+ output for 2–4 hr, after which H+ secretion increased above normal, coincident with renal HCO3– loss and metabolic acidosis. Higher doses produced a greater systemic acidosis and resulted in less initial reduction of H+ and greater augmentation. Doses of 75–100 mg/kg, given 17 hr before feeding to produce a systemic acidosis, resulted in increased secretion, even though sufficient drug remained in the plasma to inhibit tissue carbonic anhydrase. Metabolic acidosis (i.v. HCl) initially suppressed but later augmented gastric H+. Acetazolamide had no suppressive effect in the presence of either an HCl- or acetazolamide-induced acidosis. Metabolic alkalosis (i.v. NaHCO3) reduced gastric H+ in regular feeding experiments and in dogs made acidotic by acetazolamide.


1990 ◽  
Vol 48 (2) ◽  
pp. 156-160
Author(s):  
João S. Pereira ◽  
Luiz Augusto F. Andrade ◽  
Paulo H. F. Bertolucci ◽  
J. Geraldo Camargo Lima ◽  
Henrique B. Ferraz

In order to study the nigrostriatal pathway, we obtained the rotatory behavior model in male Wistar rats by electrolytic lesion of the left lateral hypothalamic region. Animals thus lesioned displayed rotations toward the same side of lesion when apomorphine was administered, a result in disagreement with what has been obtained in the model with 6-hydroxydopamine lesion. The administration of PLG alone was not followed by rotatory behavior but when the compound was administered in low doses (0.25 to 1mg/kg) simultaneously with apomorphine to animals previously submitted to REM sleep deprivation, a significant increase in the number of rotations was observed in comparison with controls and groups receiving higher doses of PLG. These results indicate that PLG may act as, a modulator on dopamine receptors in the striatum.


1990 ◽  
Vol 78 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Joe Collier ◽  
Patrick Vallance

1. The dose-response to acetylcholine has been examined in dorsal hand veins of healthy volunteers before and after removal of the endothelium. 2. Measurements were made in single dorsal hand veins during local infusions of acetylcholine. The vein was irrigated with distilled water to remove the endothelium. Dilator studies were performed in vessels preconstricted by a continuous infusion of noradrenaline. 3. In the endothelium-intact vessel the dose-response to acetylcholine was biphasic; low doses produced venodilatation with higher doses causing venoconstriction. 4. Dilatation to low doses of acetylcholine was abolished by prior irrigation with distilled water, consistent with denudation of the endothelium by this process. Irrigation augmented the constriction seen in response to higher doses of acetylcholine. 5. This is the first demonstration of an endothelium-dependent biphasic dose-response to acetylcholine in man. The results raise questions as to the possible physiological actions of endogenous acetylcholine and as to the use of the acetylcholine dose-response curve as a marker of endothelial function.


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