Role of phosphorus in activated sludge

Monod's kinetic model was used to correlate the specific growth rate of mixed activated sludge with the limiting substrate of phosphorus for both batch and continuous-flow culture systems. In the batch reactor system, the specific growth rate varied from 0.092 to 0.617 h(-1) and the saturation constant changed from 25.5 to 117.5 when the COD: P ratio was controlled within the range of 10 to 788 and at the temperature 25+/- 0.5 degrees C. An inverse relationship between specific growth rate and cell yield was found. the maximum specific growth rate and the saturation constant obtained from this study were equal to 0.64 h(-1) and 0.378mg/L, respectively. In the completely mixed continuous-flow culture system, it was found that the substrate utilization, biological solids production, and sludge composition were markedly affected by the source of phosphorus available in the wastewater. The phosphorus-limited activated sludge is normally high in carbohydrate content and low in protein content. Also, sludge organisms growth under the severely restricted phosphorus condition usually possess a large capsule. These capsulated carbohydrate-like substances can be converted to cellular protein if the source of phosphorus is added. The values of cell yield in the continuous-flow activated sludge system are predictable by the use of kinetic constants that are generated from batch culture studies.

Serological mass survey for early detection of nasopharyngeal carcinoma in Wuzhou City, China

A serological mass survey was carried out in Wuzhou City of the Guangxi Autonomous Region, China. Sera were collected from 12,932 persons between the ages of 40 and 59. The positive rate of VCA/IgA antibody-positive person was 5.3%, but no EA/IgA antibody was found in sera from VCA/Iga-negative persons. Thirteen and nine nasopharyngeal carcinoma (NPC) patients were detected from the VCA/Iga and EA/IgA antibody-positive persons, respectively. With the present combination method the detection rate of NPC for 12,932 persons was 100.5/100,000 and for 680 VCA/IgA antibody-positive persons it was 1,900/100,000. Thus, the rate was twice and 37 times higher, respectively, than the annual incidence rate of NPC in persons of the same age group from 1975-1978 in Wuzhou City. Of 13 NPC patients, 9 were in stage I (70%) and 4 in stage II (30%). Therefore, it is possible to reduce the mortality rate of NPC in Wuzhou City by radiotherapy of NPC patients in the early stage of the disease. The present results further suggest that EB virus is closely associated with NPC.

Enthalpies of Dilution of Aqueous Electrolytes: Sulfuric Acid, Hydrochloric Acid, and Lithium Chloride

Calorimetric measurements at 25 °C of the enthalpies of dilution of aqueous H₂SO₄ (0.00090 to 6.4 mol · kg^-1), LiCl (0.026 to 6.7 mol · kg^-1), and HCl (0.018 to 1.6 mol · kg^-1) have been performed using two different isothermal calorimeters. The results of this work and that of three earlier calorimetric investigations and one Raman spectral investigation have been used to calculate values of the relative apparent molal enthalpies, and relative partial molal enthalpies for these electrolytes.

Brain sulfatide and non-lipid sulfate metabolism in leucodystrophic (jimpy) mice

In leucodystrophic (jimpy mutant) mice there is a marked depletion of brain sulfatide as compared to normal ilttermates. Subcellular fractionation showed decreased sulfatide concentrations in microsomal and synaptosomal fractions prepared from jimpy brains. The in vivo incorporation of 35SO4 into sulfatide of myelin, microsomal, mitochondrial and synaptosomal fractions was significantly inhibited in the jimpy mutant. In addition, the incorporation of 35SO1 into non-lipid brain membrane components (sulfated glycoproteins and mucopolysaccarides) was also decreased in jimpy mice. These results suggest that the jimpy mutation produces widespread alterations in brain sulfatide metabolism and also affects the metabolism of non-lipid membrane components of brain.

Prevalence of cytoplasmic antibodies in systemic lupus erythematosus

Prevalence of cytoplasmic antibodies--smooth muscle antibodies (SMA), gastric parietal cell antibodies (GPA), and mitochondrial antibodies (MTA)--was evaluated in 148 normal persons and 168 patients by indirect immunofluorescent method. Their prevalence in normal persons was 0%, 2% and 0% for SMA, GPA and MTA respectively, while SMA and MTA were positive in 5.7% and 8.6% of the 35 systemic lupus erythematosus (SLE) patients respectively. The difference in the prevalence of SMA and MTA between these two groups was statistically significant. The higher prevalence of these antibodies and the occurrence of various kinds of antibodies in SLE patients support the thesis that SLE is an autoimmune phenomenon.