ABSTRACT
A silicon crystal was used to channel and extract 70 GeV protons from the U-70 accelerator with an efficiency of 85.3+/-2.8%, as measured for a beam of approximately 10(12) protons directed towards crystals of approximately 2 mm length in spills of approximately 2 s duration. The experimental data follow very well the prediction of Monte Carlo simulations. This demonstration is important in devising a more efficient use of the U-70 accelerator in Protvino and provides crucial support for implementing crystal-assisted slow extraction and collimation in other machines, such as the Tevatron, RHIC, the AGS, the SNS, COSY, and the LHC.
ABSTRACT
The influence of difuracil (PAP-49), a novel nitrofuran, on saprotrophic and normal digestive tract microflora was studied in vitro and in vivo by comparison with that of furazolidone. It was shown that the minimum inhibitory concentration of both the drugs ranged from 0.01 to 1.56 micrograms/ml. The experiments on rabbits with the use of the drugs in doses of 5 and 10 mg/ kg body weight revealed that unlike furazolidone difuracil induced no noticable qualitative or quantitative changes in the intestinal microflora composition.
Subject(s)
Anti-Bacterial Agents/toxicity , Intestines/drug effects , Administration, Oral , Animals , Anti-Bacterial Agents/administration & dosage , Culture Media , Dose-Response Relationship, Drug , Furazolidone/toxicity , Intestines/microbiology , Microbial Sensitivity Tests , Nitrofurans/administration & dosage , Nitrofurans/toxicity , RabbitsABSTRACT
A new nitrofuran, N-(5-nitrofurfurilidene)-5-nitrofuran-2-(N'-acetyl)carboxamidra zone designated as PAP-49 was synthesized. With the method of two-fold serial dilutions in the Hottinger's broth it was demonstrated that by its antimicrobial activity against cocci and enterobacteria PAP-49 was not inferior and in some cases it was even superior to such antibiotics and chemical drugs as benzylpenicillin, streptomycin, tetracycline, chloramphenicol, erythromycin, gentamicin, nitoxolin and furazolidone. The further study of the antibacterial properties of the new nitrofuran with the use of 101 strains of 16 bacterial species showed that its MICs for gram positive and gram negative bacteria were 0.03-3.13 and 0.78-125.0 micrograms/ml respectively. Combination of PAP-49 in the subbacteriostatic concentrations with other antimicrobial agents provided a 2-8-fold increase in the antimicrobial effect. The highest synergism was observed when nitrofuran was used in combination with aminoglycosides, benzylpenicillin or levomycetin. The primary screening revealed that PAP-49 belongs to the group of low toxic substances. Its LD50 after the oral administration to albino mice was 4631.9 mg/kg. The compound did not practically cumulate in the animal organism.
Subject(s)
Anti-Bacterial Agents/pharmacology , Enterobacteriaceae/drug effects , Gram-Positive Cocci/drug effects , Animals , Anti-Bacterial Agents/toxicity , Drug Evaluation, Preclinical , Drug Synergism , Lethal Dose 50 , Mice , Microbial Sensitivity Tests , Nitrofurans/pharmacology , Nitrofurans/toxicityABSTRACT
The therapeutic efficacy of a new nitrofuran, N-(5-nitrofurilidene)-5-nitrofuran-2-(N'-acetyl)carboxamidra zone (difuracil or PAP-49) in experimental staphylococcal and Coli septicemia was stated and compared to that of furazolidone. It was shown in the models of staphylococcal and Coli septicemia of albino mice that by its therapeutic efficacy difuracil (PAP-49) was 1.3 times more active as furazolidone and by 1-2 days earlier eradicated the pathogens in the host.
