Search results for "Calcium"

Non-linear dielectric behaviour and glass phase in Sr1-xCaxTiO3(x= 0.002 andx= 0.003)

1999

This work reports a study of the temperature and electric field dependence of the dielectric constant of strontium calcium titanate. The first part of the paper is focused on the analysis of a mean-field model for the polar clusters generated by the random impurities of calcium. It is shown that the dipolar moments within each cluster can be represented by an equivalent quantum two-level system. General expressions for the temperature and field dependence of the Edward-Anderson order parameter and of the electrical polarization are given. Analytical solutions are also obtained in the limit of high temperatures and in the limit of high tunnelling frequencies. The second part of the work repo…

Identification of binding peptides on calcium silicate hydrate: a novel view on cement additives.

2014

Cement is the most used industrial product in the world. Although the chemical composition of the material has stayed more or less the same since its discovery by the Romans around 2000 years ago, [ 1 ] the performance has been increased by chemical additives. Spectacular buildings like the Willis Tower in Chicago, Taipei 101 or lately the over 800 m high Burj Khalifa in Dubai were realizable thanks to the development of high performance building materials. [ 2 ] Not only for such prestige objects but also in daily building processes, the trend goes towards always higher buildings because of the continued urbanization which was identifi ed already in 1982 as one of the so-called “megatrends…

Determination of Calcium in Certain Fertilizers by Inductively Coupled Plasma Atomic Emission Spectrometry: Studies of Some Spectral and Interelement…

1997

Abstract Four analytical wavelengths (393.366, 396.847, 317.933, and 422.673 nm) were used to determine Ca in 2 fertilizers by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Matrix effects were studied by adding to real fertilizer solutions fertilizer elements that are known or believed to interfere with Ca determination. Matrix effects were calculated by multiple linear regression. Interference was caused by S, K, or B. At 422.673 nm, the interference of B and K is a spectral effect, and at 396.847 and 317.933 nm, the interference of S and K is an interelement effect. At 393.366 nm, no linear interference was found. The best wavelength for determining Ca in fertilizers …

Combined treatment with bexarotene and rosuvastatin reduces angiotensin-II-induced abdominal aortic aneurysm in apoE−/−mice and angiogenesis

2015

Background and Purpose Abdominal aortic aneurysm (AAA) is a degenerative vascular disease associated with angiogenesis. Bexarotene is a retinoid X receptor (RXR) ligand with anti-angiogenic activity. Statins also exert anti-angiogenic activity and activate PPARs. Because RXR ligands form permissive heterodimers with PPARs and a single anti-angiogenic drug may not be sufficient to combat the wide array of angiogenic factors produced during AAA, we evaluated the effect of combined low doses of bexarotene and rosuvastatin in a mouse model of AAA.

Are morphology and composition of gallstones related? An x-ray diffraction study

1994

Abstract An x-ray diffractometric technique was used to study the crystalline composition of gallstones removed during surgery from 106 patients. Monohydrate cholesterol was found in the stones of 70 (66%) patients, either alone (33%) or in association with calcium salts (33%). The anhydrous form of cholesterol was found in the stones of 28 (26%) patients, either alone (10%) or in association with calcium salts (16%). These salts (vaterite, aragonite, and calcite) were found in 50% of cases in varying amounts (from 12% to 15% of the stone weight). Eight stones contained no cholesterol: 4 showed an amorphous pattern and 4 were composed of calcium carbonate salts. In 7 of 8 patients with bile…

The ionic dependence of calcium efflux from guinea pig auricles.

1968

�ber den Einflu� von Digitoxigenin auf das Aktionspotential des Vorhofs euthyreoter und hyperthyreoter Meerschweinchen bei experimentellen Insuffizie…

1961

An isolierten Herzohren von Meerschweinchen wurden intracellulare Aktionspotentiale unter gleichzeitiger Registrierung der Kontraktionen abgeleitet. Untersucht wurde der Einflus des Digitoxigenins nach Barbituratschadigung und unter Calciummangel bei euthyreoten und hyperthyreoten Tieren.

Low endotoxemia prevents the reduction of gastric blood flow induced by NSAIDs: role of nitric oxide

2003

1 The role of nitric oxide (NO) in the effects of low endotoxemia on gastric damage and blood flow has been evaluated in indomethacin-treated rats. 2 Pretreatment (-1 h) with endotoxin (40 micro g kg(-1)) reduced gastric damage induced by indomethacin (20 mg kg(-1)) in conscious rats. 3 Endotoxin prevented the reduction in gastric blood flow (laser Doppler flowmetry) induced by indomethacin in pentobarbital-anaesthetised rats. 4 Pretreatment with an NO-synthase (NOS) inhibitor (L-NAME, 1 mg kg(-1)) reversed the protective effect of endotoxin on gastric blood perfusion. 5 Endotoxin did not modify the expression of mRNA for endothelial NOS or inducible NOS in the gastric corpus when evaluated…

�ber die Wirkung von Digitoxigenin auf den cellul�ren Calcium-Umsatz im Herzmuskelgewebe

1962

In vivo hypotensive activity ofPistacia lentiscus L

1988

The present studies were undertaken to explain the mechanism of action of the hypothesive effect of Pistacia lentiscus L. aqueous extract. The potassium, calcium and magnesium content of the aqueous extract was determined and synthetic mixtures of salts evaluated in rats. The urinary excretion volume and the sodium and potassium concentrations in urine were also determined. In an effort to explain the effects of the extract, in vivo pharmacological experiments were conducted.