Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) and dicalcium phosphate anhydrous (Ca(H2PO4)2, DCPA) were coated onto titanium substrates using the thermal substrate method in an aqueous solution containing calcium and phosphate ions at 150◦C with pH values in the range 4–8. Specimens with the HAp and DCPA layer were immersed in a simulated body fluid (SBF) to examine the dissolution and induced HAp grow...

Phosphodiester linkages, including those that join the nucleotides of DNA, are highly resistant to spontaneous hydrolysis. The rate of water attack at the phosphorus atom of phosphodiesters is known only as an upper limit, based on the hydrolysis of the dimethyl phosphate anion. That reaction was found to proceed at least 99% by C-O cleavage, at a rate suggesting an upper limit of 10(-15) s(-1)...

Ammonium sulfate, as well as potassium phosphate, can be used to measure solubility differences between hemoglobin S and hemoglobin A. In addation, the solubility of deoxyhemoglobin C(Harlem) in 1.96 M phosphate has a markedly different temperature dependence from that of deoxyhemoglobin S. This observation indicates that the solubility measurement is quite sensitive to changes in protein struc...

Upon ethyl nitrosourea treatment of RNA of tobacco mosaic virus, up to four phosphodiester groups may be alkylated per molecule without chain breakage, as shown be sucrose gradient centrifugation. This indicates that ribophosphotriesters are quite stable. However, when this alkylation reaction is of longer duration and 6 to 10 triesters are formed, then an average of 1 to 2 breaks occurs and li...

60 adult Rattus novergicus (both sexes) of mean body weight of 150.0±3.5g were distributed into six groups of ten rats per group (same sex). The groups A, B, C, D, E and F were exposed to adjusted dosages of 0%, 20%, 40%, 60%, 80% and 100% of DDVP respectively by inhalation from day 1 to day 28. Biochemical analysis indicated that DDVP caused significant decrease (p<0.05) in GPT activity, WBC a...

We examined the effects of a variety of amendments on the consumption of [U-C]dimethyl sulfide in a Georgia salt marsh. Methylated compounds, particularly those with dimethyl groups, significantly inhibited dimethyl sulfide consumption, while nonmethylated substrates had little effect. Dimethyl disulfide and dimethyl ether were the most effective inhibitors tested.

The effect of introducing methyl groups into DNA substrates was studied by using the spleen exonuclease (EC 3.1.4.1), an enzyme which hydrolyses oligonucleotides in a sequential manner by splitting off 3'-phosphomononucleotides starting from the 5'-hydroxyl terminus. Analyses of oligodeoxyribonucleotide 3'-phosphate substrates after reaction in vitro with dimethyl sulphate demonstrated that the...

A practical technique for isolation and cryopreservation of tench (Tinca tinca) (Cyprinidae, Teleostei) early stages of germ cells (GC), including spermatogonia and spermatocytes, is reported for the first time. The germ-line cells possess the ability to differentiate into functional gametes of both sexes. These early stages of germ cells are small enough to be well-suited to cryopreservation, ...

Glycosomes, the microbody-like organelles containing mainly glycolytic enzymes, were purified from the long slender bloodstream form of Trypanosoma brucei EATRO 110 monomorphic strain by an improved method in which the protozoa were frozen and thawed in 15% glycerol to free, from the plasma membrane, much of the variant surface glycoprotein which used to constitute the major contaminant of our ...

a study was carried out on totally chlorine-free (tcf) bleachability of dimethyl formamide (dmf) treated bagasse pulps exposed to cz-3 and fp 90031-sp strains of white-rot fungus ceriporiopsis subvermispora. this process involved an oxygen and peroxide stage bleaching sequence. the effect of enzymatic stage on bleachability properties was studied and compared with control pulps, processed witho...