The purpose of this study was to determine the mechanisms by which organic calcium channel blockers inhibit cerebral vasoconstriction. Isolated bovine middle cerebral arteries were cut into rings to measure contractility or into strips to measure radioactive calcium (45Ca) influx and efflux. Calcium channel blockers (10(-5) M verapamil or 3.3 X 10(-7) M nifedipine) and calcium-deficient solutio...

Bolivia and Chile. These diverse countries hold not only striking beauty throughout these regions, but also vast natural resources. In the Atacama Desert region, the discovery of such important natural resources have left residual problems lingering in the economic and political relations between these South American nations, and still cause tensions today. This paper explores historic disputes...

The aim of this study is to investigate the nitrate adsorption on granular ferric hydroxide (GFH). The effect of factors such as initial concentration of nitrate, pH, contact time, and adsorbent mass were determined. The study was done in laboratory–scale in which synthetic nitrate solutions in a batch reactor were placed in contact with the adsorbent to model adsorption kinetics. It was found ...

In China, excessive use of nitrogen fertilizers in glasshouses leads to nitrate accumulations in soil and plants, which then limits productivity. Melatonin, an evolutionarily highly conserved molecule, has a wide range of functions in plants. We analyzed the effects of melatonin pretreatment on the growth, mineral nutrition, and nitrogen metabolism in cucumber (Cucumis sativus L. "Jin You No. 1...

If a sartorius muscle of frog is pretreated for 30 min. with a hyposmotic Ringer's (called "hyposmotic potassium chloride") in which all sodium chloride is replaced by 23 mM potassium chloride, and then is immersed in normal Ringer's for about 40 min., a twitch of normal size can be elicited although the potassium contracture is almost completely abolished. During the time that this selective i...

Conventional soil analyses are time-consuming; therefore, the quick test (QT) method is needed. This study was to assess accuracy of pH, N-nitrate, available phosphorus (P), and exchangeable potassium (K) analysis determined by QT developed Akvo calibrated with standard laboratory methods. The field research collected 131 samples, from horticultural lands in 4 regencies within East Java-Indones...

The existing evidence for the nature of the phase diagram for the binary system sodium nitrate-potassium nitrate is reviewed and in particular whether the system is of the continuous solid solution type, as has often been stated in the last 80 years, or whether this system is of the eutectic type as was earlier believed and has again been asserted recently. Additional evidence from Raman spectr...

increased nitric oxide (no) formation is mechanistically linked to pathophysiology of the extrahepatic complications of cirrhosis. no is formed by either enzymatic or non-enzymatic pathways. enzymatic production is catalyzed by no synthase (nos) while entero-salivary circulation of nitrate and nitrite is linked to non-enzymatic formation of no under acidic ph in the stomach. there is no data on...