this study was carried out in order to determine the effects of boron and cold stress on pollen germination of almond hybrids in vitro culture, two different media including the absence and presence of boron (0 mg/l, and 100 mg/l) in 10% sucrose and 1% agar medium at 24°c in dark conditions. the results showed that different treatments had a significant effect on the germination percentage. the...

Solid-state potassium-39 NMR spectra of two potassium complexes of crown-ether-based organic ligands (1.KI and 2) have been acquired at 11.75 and 21.1 T and interpreted to provide information on the 39K quadrupolar and chemical shift tensors. The analyses reveal a large potassium chemical shift tensor span of 75+/-20 ppm for 1.KI. This appears to be the first such measurement for potassium in a...

We identified a gene responsible for tolerance to boron (B) toxicity in rice (Oryza sativa), named BORON EXCESS TOLERANT1. Using recombinant inbred lines derived from the B-toxicity-sensitive indica-ecotype cultivar IR36 and the tolerant japonica-ecotype cultivar Nekken 1, the region responsible for tolerance to B toxicity was narrowed to 49 kb on chromosome 4. Eight genes are annotated in this...

An existing technique for accurate measurement of iron in silicon, which was previously restricted to low injection and a narrow doping range, has been extended to arbitrary injection and doping levels. This allows contactless lifetime measurement techniques to be used for very sensitive and rapid iron detection under a wide range of conditions. In addition, an easily measured and unambiguous ‘...

Potassium and calcium salts are well known catalysts for the reaction between carbon and O2. Current airport runway deicing agents typically use formulations containing alkali or alkaline-earth metals (see C&E News, 01/01/01, p. 30). Very effective oxidation protection of aircraft brakes is thus of great practical and fundamental interest. Phosphorus and boron compounds are known to inhibit unc...

A new method for the synthesis of Cl-BODIPYs from F-BODIPYs is reported, merely requiring treatment of the F-BODIPY with boron trichloride. Cl-BODIPYs are exploited as synthetic intermediates generated in situ for the overall conversion of F-BODIPYs to O- and C-BODIPYs in high overall yields using a mild one-pot procedure. This route enables F-BODIPYs to be transformed into derivatives that are...

PREVIOUS STUDIES from this laboratory have indicated that cardiac patients who have been successfully treated for congestive heart failure and who have become free from edema have a larger than normal concentration of sodium in their bodies." 2 The suggestion was advanced that part or all of the sodium excess in such patients represented osmotically inactive cation because the patients studied ...

As early as 1854 Knop proposed the use of potassium bromate and hyclrobromic acid for the determination of Iodine values and lately again Tolle (J. Pharm. Chem, 1905, 31, 111 and 183) and Mossier (Ph^n. Zeit., 1907) have proposed the use of Bromine from one source or another for the determination of the degree of unsaturation of fats. Mossier uses a mixture of potassium bromate and bromide acid...

Metal-free transformations of organotrifluoroborates are advantageous since they avoid the use of frequently expensive and sensitive transition metals. Lewis acid-catalyzed reactions involving potassium trifluoroborate salts have emerged as an alternative to metal-catalyzed protocols. However, the drawbacks to these methods are that they rely on the generation of unstable boron dihalide species...

The relation between serum potassium level and all-cause mortality was examined in a prospective study of 7,636 middle-aged British men followed for 11.5 years (1978-1991). Men being treated for hypertension had a significantly lower mean (+/- standard error) potassium level than men not in treatment (4.24 +/- 0.03 mmol/liter vs. 4.32 +/- 0.01 mmol/liter; p < 0.01). During the follow-up period ...