Search results for "CALCIUM"

Isobaric Vapor−Liquid Equilibria for 1-Propanol + Water + Calcium Nitrate

1999

Isobaric vapor−liquid equilibria for all of the binary and ternary mixtures of 1-propanol, water, and calcium nitrate have been measured at 100.00 kPa using a recirculating still. The addition of calcium nitrate to the solvent mixture produced an important salt effect; the azeotrope was removed at salt mole fractions higher than 0.08. The three experimental binary data sets were independently fitted with the electrolyte NRTL model (Mock, B.; Evans, L. B.; Chen, C. C. AIChE J. 1986, 32, 1655−1664), and the parameters of Mock's model were estimated for each binary system. No ternary parameter was required. These parameters were used to predict the ternary vapor−liquid equilibrium using the sa…

Casein phosphopeptides released by simulated gastrointestinal digestion of infant formulas and their potential role in mineral binding

2006

Abstract Adapted and follow-up milk-based infant formulas were subjected to gastrointestinal digestion simulating physiological conditions. The naturally occurring casein phosphopeptides (CPPs) generated were fractionated by anion exchange high-performance liquid chromatography and sequenced by tandem mass spectrometry. In both infant formula digests, a total of 19 CCPs from bovine casein were identified, of which 7 corresponded to α s1 -casein and 12 to α s2 -casein. Most CPPs had the cluster sequence SpSpSpEE, representing the binding sites for minerals. The distribution of calcium, iron and zinc content in CPP fractions eluted from the anion exchange column was also studied. The results …

EDTA excess Zn(II) back-titration in the presence of 4-(2-pyridylazo)-resorcinol indicator and naphthol green beta as inert dye for determining Cr(II…

2006

The colour changes of 4-(2-pyridylazo)-resorcinol and naphthol green beta as new screening metallochromic indicator in back-titration of EDTA excess with Zn(II) to determine Cr(III)/EDTA complex was investigated with the help of tristimulus colorimetry. Specific colour discrimination (SCD) and L*, a*, b* 1976 parameters were successfully applied to evaluate the quality of colour transition at the end-point in non-alkaline media and in the presence of Zn(II) and Ca(II) which resulted in non-interfering species at 1x10(-3) M and 2x10(-3) M, respectively. The above concentrations are comparable with those used for Cr(III). Validation of the fast and accurate reported method was performed by at…

Cr(VI)/Cr(III) and As(V)/As(III) Ratio Assessments in Jordanian Spent Oil Shale Produced by Aerobic Combustion and Anaerobic Pyrolysis

2011

With the increase in the awareness of the public in the environmental impact of oil shale utilization, it is of interest to reveal the mobility of potentially toxic trace elements in spent oil shale. Therefore, the Cr and As oxidation state in a representative Jordanian oil shale sample from the El-Lajjoun area were investigated upon different lab-scale furnace treatments. The anaerobic pyrolysis was performed in a retort flushed by nitrogen gas at temperatures in between 600 and 800 °C (pyrolytic oil shale, POS). The aerobic combustion was simply performed in porcelain cups heated in a muffle furnace for 4 h at temperatures in between 700 and 1000 °C (burned oil shale, BOS). The high loss-…

Paradoxical effect of increased diastolic Ca(2+) release and decreased sinoatrial node activity in a mouse model of catecholaminergic polymorphic ven…

2012

Background— Catecholaminergic polymorphic ventricular tachycardia is characterized by stress-triggered syncope and sudden death. Patients with catecholaminergic polymorphic ventricular tachycardia manifest sinoatrial node (SAN) dysfunction, the mechanisms of which remain unexplored. Methods and Results— We investigated SAN [Ca 2+ ] i handling in mice carrying the catecholaminergic polymorphic ventricular tachycardia–linked mutation of ryanodine receptor (RyR2 R4496C ) and their wild-type (WT) littermates. In vivo telemetric recordings showed impaired SAN automaticity in RyR2 R4496C mice after isoproterenol injection, analogous to what was observed in catecholaminergic polymorphic ventricul…

A fifth class of antiarrhythmic action?

1981

Cellular Mechanisms of Subplate-Driven and Cholinergic Input-Dependent Network Activity in the Neonatal Rat Somatosensory Cortex

2008

Early coordinated network activity promotes the development of cortical structures. Although these early activity patterns have been recently characterized with respect to their developmental, spatial and dynamic properties, the cellular mechanisms by which specific neuronal populations trigger coordinated activity in the neonatal cerebral cortex are still poorly understood. Here we characterize the cellular and molecular processes leading to generation of network activity during early postnatal development. We show that the somatosensory cortex of newborn rats expresses cholinergic-driven calcium transients which are synchronized within the deeply located subplate. Correspondingly, endogen…

Corrosion of Heritage Objects: Collagen‐Like Triple Helix Found in the Calcium Acetate Hemihydrate Crystal Structure

2020

Abstract Helical motifs are common in nature, for example, the DNA double or the collagen triple helix. In the latter proteins, the helical motif originates from glycine, the smallest amino acid, whose molecular confirmation is closely related to acetic acid. The combination of acetic acid with calcium and water, which are also omnipresent in nature, materializing as calcium acetate hemihydrate, was now revealed to exhibit a collagen‐like triple helix structure. This calcium salt is observed as efflorescence phase on calcareous heritage objects, like historic Mollusca shells, pottery or marble reliefs. In a model experiment pure calcium acetate hemihydrate was crystallized on the surface of…

Novel Biodegradable Composite of Calcium Phosphate Cement and the Collagen I Mimetic P-15 for Pedicle Screw Augmentation in Osteoporotic Bone

2021

Osteoporotic vertebral fractures often necessitate fusion surgery, with high rates of implant failure. We present a novel bioactive composite of calcium phosphate cement (CPC) and the collagen I mimetic P-15 for pedicle screw augmentation in osteoporotic bone. Methods involved expression analysis of osteogenesis-related genes during osteoblastic differentiation by RT-PCR and immunostaining of osteopontin and Ca2+ deposits. Untreated and decalcified sheep vertebrae were utilized for linear pullout testing of pedicle screws. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DEXA). Expression of ALPI II (p &lt

Intact parathyroid hormone value on the first postoperative day following total thyroidectomy as a predictor of permanent hypoparathyroidism: a retro…

2022

Introduction: Hypoparathyroidism represents a common complication following total thyroidectomy. To date, there is still no reliable and immediate postoperative parameter to establish which patients with postsurgical hypoparathyroidism will develop permanent hypoparathyroidism. The main purpose of the present study was to assess whether the intact parathyroid hormone (iPTH) value on the first postoperative day is a good predictor of permanent hypoparathyroidism. Material and methods: Patients undergoing thyroidectomy in our unit between March 2018 and January 2020 were analysed. According to the iPTH value on the first postoperative day and on the basis of the detection threshold of the iPT…