A recently suggested mechanism for the stress memory of various metal phosphates is investigated experimentally. Based on first-principles simulations [N. J. Mosey et al., Science 307, 1612 (2005)], it had been argued that atoms with flexible coordination, such as zinc or heavy-metal cations, act as network-forming agents, undergoing irreversible pressure-induced changes in bonding that lead to...

In this study we present x-ray diffraction data on metal phosphates containing either high or low coordination number zinc or calcium. The experiments reveal that low-coordination zinc phosphate crystals are relatively soft at ambient conditions but stiffen dramatically with pressure, p, thereby exhibiting smart materials behavior. In comparison, high-coordination zinc and calcium phosphates ha...

Renomedullary interstitial cells cultured from the Dahl salt-resistant rat have higher levels of basal cytosolic calcium and prostaglandin E2 and are more responsive to vasopressin than interstitial cells from the Dahl salt-sensitive rat. We examined the potential role of inositol phospholipid hydrolysis in mediating these differences. Vasopressin-induced increases in labeled inositol phosphate...

The aim of the present study was to evaluate the effects of experimental saliva substitutes based on carboxymethyl cellulose (CMC) differing in degrees of saturation with respect to calcium phosphates on the mineral loss of enamel in vitro. Demineralized bovine specimens (subsurface lesions) were exposed to one of six experimental CMC-based solutions with theoretical degrees of saturation with ...

Calcium phosphate cements (CPC) are valuable bone fillers. Recently they have been also considered as the basis for drug-, growth factors- or cells-delivery systems. Broad possibilities to manipulate CPC composition provide a unique opportunity to obtain materials with a wide range of physicochemical properties. In this study we show that CPC composition significantly influences cell response. ...

To define the minimum and maximum levels for calcium concentration of dialysis fluid a combination of acute and long-term observations was carried outIn acute experiments the external calcium balance during dialysis was dependent on the gradient between plasma ultrafilterable calcium and dialysis fluid calcium concentration. Changes in plasma calcium during dialysis did not correlate with measu...

Several reports have mentioned the existence of non-apatitic environments of phosphate and carbonate ions in synthetic and biological poorly crystalline apatites. However there were no direct spectroscopic evidences for the existence of non-apatitic environment of calcium ions. Xray Absorption Spectroscopy, at the K-edge of calcium, allows the discrimination between different calcium phosphates...

Biofortification of commonly eaten staple food crops with essential mineral micronutrients is a potential sustainable solution to global micronutrient malnutrition. Because phytic acid (PA; 1,2,3,4,5,6-hexakis myo-inositol) reduces mineral micronutrient bioavailability, reduction of PA levels could increase the bioavailability of biofortified iron (Fe), zinc (Zn), calcium (Ca), and magnesium (M...

Emulsifying salts (ES) are used for process cheese production, however, it is not completely understood how ES influence the physical and chemical properties of process cheese. The purpose of this study was to understand the interactions between ES and milk proteins using a simple model system. In this system, milk protein concentrates (MPC) solution was used as the source of milk protein and t...

Calcium phosphate is attracting attention as a bone repair material and controlled-release carrier of various drugs such disease therapeutic agents anticancer agents. Compared with some bioabsorbable polymers, calcium phosphates have the advantage preventing pH decrease in surrounding body fluid. However, there are few studies comparing effect supporting substances different physicochemical pro...