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M Mateev

Publications and source records attributed to M Mateev.

15 recordsLinked to original sources
PubMed2005

Omega- and Omega+ production in central Pb + Pb collisions at 40 and 158A GeV.

Results are presented on Omega production in central Pb+Pb collisions at 40 and 158A GeV beam energy. For the first time in heavy ion reactions, rapidity distributions and total yields were measured for the sum Omega(-) + Omega(+) at 40A GeV and for Omega(-) and Omega(+) separately at 158A GeV. The yields are strongly underpredicted by the string-hadronic UrQMD model but agree better with predictions from hadron gas models.

Journal Article↗
PubMed2005

System-size dependence of strangeness production in nucleus-nucleus collisions at squareroot[sNN]=17.3 GeV.

Emission of pi+/-, K+/-, phi, and Lambda was measured in near-central C+C and Si+Si collisions at 158 AGeV beam energy. Together with earlier data for p+p, S+S, and Pb+Pb, the system-size dependence of relative strangeness production in nucleus-nucleus collisions is obtained. Its fast rise and the saturation observed at about 60 participating nucleons can be understood as the onset of the formation of coherent systems of increasing size.

Journal Article↗
PubMed2004

Lambda and lambda production in central Pb-Pb collisions at 40, 80, and 158A GeV.

Production of Lambda and Antilambda hyperons was measured in central Pb-Pb collisions at 40, 80, and 158A GeV beam energy on a fixed target. Transverse mass spectra and rapidity distributions are given for all three energies. The Lambda/pi ratio at midrapidity and in full phase space shows a pronounced maximum between the highest BNL Alternating Gradient Synchrotron and 40A GeV CERN Super Proton Synchrotron energies, whereas the Lambda/pi ratio exhibits a monotonic increase.

Journal Article↗
PubMed2004

Evidence for an exotic S= -2, Q= -2 baryon resonance in proton-proton collisions at the CERN SPS.

Results of resonance searches in the Xi(-)pi(-), Xi(-)pi(+), Xi;(+)pi(-), and Xi;(+)pi(+) invariant mass spectra in proton-proton collisions at sqrt[s]=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi(-)pi(-) baryon resonance with mass of 1.862+/-0.002 GeV/c(2) and width below the detector resolution of about 0.018 GeV/c(2). The significance is estimated to be above 4.2sigma. This state is a candidate for the hypothetical exotic Xi(--)(3/2) baryon with S=-2, I=3 / 2, and a quark content of (dsdsū). At the same mass, a peak is observed in the Xi(-)pi(+) spectrum which is a candidate for the Xi(0)(3/2) member of this isospin quartet with a quark content of (dsus[-]d). The corresponding antibaryon spectra also show enhancements at the same invariant mass.

Journal Article↗
PubMed1994

Superiority of Nd:YAG laser to cryosurgery in the treatment of rectal carcinoma.

Laser coagulation (LC) by Nd:YAG laser and cryodestruction (CD) by insulated cryoprobe were done in 52 patients with carcinoma of the rectum (LC = 27, CD = 25). The patients were divided into four groups: group I, inoperable rectal carcinoma because of advanced stage of malignancy, severe concomitant disease, old age (LC = 14, CD = 12); group II, patient refused permanent colostomy (LC = 4, CD = 3); group III, polypoid lesion fulfilled the criteria of local excision (LC = 3, CD = 2); group IV, local recurrence after anterior resection (LC = 6, DC = 8). The mean hospital stay was 8.11 +/- 5.6 days for LC and 12.8 +/- 8.7 days for CD (p less than 0.05). For LC minimal or no sedation was needed, but for CD general anesthesia (n = 3) was occasionally necessary. Significant improvement was achieved in 85.18% (n = 23) of cases with LC and 56% (n = 14) of cases with CD (p less than 0.05). Complications after LC were mild (n = 7) to moderate (n = 3) and after CD they were moderate (n = 11) to severe (n = 2). Almost every patient with CD complained of moderate to severe discharge of malodorous necrotic tissue for a period of 2 weeks or more. In groups I, II, and IV patients with LC enjoyed a longer (81.08 +/- 47.48 days) trouble-free period than those with CD (43.3 +/- 13.45 days) (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1980

[Elimination of multidrug resistance in E. coli in calves in vivo with rimactan].

An experiment was carried out for eliminating the multimedicinal resistance markers of E. coli, populating the intestinal tract of calves, in vivo with rimactan introduced per os, and rationed 10 mg/kg of live weight, once during a period of 8 days. The highest percentage and the longest elimination were observed for the neomycin, the novobiocin and the chlornitromycin resistance markers. The elimination was weaker for the erythromycin, the streptomycin and the kanamycin markers and the weakest was for the penicillin and tetracycline markers. There appeared a difference in the elimination of the resistance markers with the different calves, especially for the markers with a low degree of elimination, depending on the individual peculiarities of the calves. Riphamycin proved to be an eliminating means for the resistance markers of E coli in vivo of calves suffering from enteritis. Alongside with the elimination of the resistance markers, due to the treatment of calves with rimactan, an almost complete recovery was achieved. Rimactan is a reliable means for fighting enteric illnesses with calves, caused by enteropathogenic E. coli.

Animals↗
PubMed1980

[Attempt at eliminating the multiple drug resistance of E. coli in pigs with enteritis using Rimactin].

The eliminating effect of rimactan was studied in vivo on resistance markers of E. coli, isolated from 18 new-born pigs with a clinic of enteritis. Rimactan is given per os in 15 mg/kg, liver weight, once a day in the course of 6 days. The sensitivity of the strains eliminated was checked in vitro in respect of 16 medicinal preparations (Pe, Sm, Km, Neo, Chl, Novo, Te, Er, Ty, Sp, Le, Am, Ox, Oxte, Ge-penicillin, streptomycin, kanamycin, neomycin, chlornitromycin, novobiocin, tetracycline, erythromycin, tylan, spectam, lentamycin, ampicillin, oxacillin, oxytetracycline, gentamicin and borgal). To 11 of them E. coli were resistant. After a treatment with rimactan an elimination of resistance markers was observed right on the first day, namely, with regard to Sm, Chl, Novo, Te, Er, Sp, Oxte. On the second day was eliminated the Pe-marker, on the third--the Ty-marker, and it was not until on the fifth day that Am and Ox-markers were eliminated. The elimination frequency was the highest between the third and the fifth days. The experiments studied also the sensitivity of the investigated coli strains with regard to different rimactan concentrations (2-256 mg/cm3) in vitro. It was most pronounced for a concentration of 16-32 mg/cm3. It was proved that rimactan can be used as a preparation for eliminating resistance markers (R-factors) of E. coli in pigs suffering from enteritis.

Animals↗
PubMed1978

[Experimental immunologic study of a protective anthrax preparation].

Rabbits and sheep immunized with protective anthrax preparation and live anthrax vaccines were examined. Protective anthrax preparation caused changes characteristic of general immunomorphology and immunomorphological reaction of the humoral type. A marked resistance in infection with the virulent anthrax culture was revealed in the animals immunized with this preparation and in those--with live vaccines. Skin allergic reactions were more intensive in sheep immunized with live Ikhtiman's vaccine; there was no reaction in the animals immunized with the protective preparation.

Animals↗
PubMed1977

[Transfer of multi-drug resistance in vivo by salmonellae and shigella in white mice].

The oral infection accomplished by 0.3 cm3 X 10(10) microbial bodies of Salmonella heidelberg and Shigella sonnei in albino mice the pathogens were found to localize in the intestines. The Salmonellae were detected up to the 10th day, and the Shigellae--up to the 14th day. Both Shigella and Salmonella transferred multi-drug resistance to some enterobacteria--E. coli and Proteus as well as to Salmonella typhimurium when the latter was also present in the intestinal tract; of these some 10--40 per cent acquire the multi-drug resistance of Salmonella heidelberg and Shigella sonnei. This type of resistance was most often transferred en bloc for the six, resp., eight markers. On some occasions segregation was observed with the transference of particular markers only.

Animals↗
PubMed1975

[Use of protective anthrax antigen in agglutination reactions].

The latex- and hemagglutination tests were applied to determination of the titres of anthrax antibodies in the sera of 982 immunized sheep. Monodispersive standard colur latex of polymethylmetacrylate and protective anthrax antigen was used in these tests. On the basis of the results of titration of control sera titres of anthrax antibodies over 1:16 in the latex- and hemagglutination tests were accepted as positive. There was revealed no difference between the sera of the immunized animals reacting positively in both tests (d = 1.87 less than delta = 2.94 at P = 0.95). The difference between the positive titres determined in the latex-agglutination (55.78%) and hemagglutination (44.41%) tests was significant (d = 11.37 less than delta = 4.39 at P = 0.95). Consequently, both tests could be used for the purpose of determination of anthrax antibody titres, but the latex-agglutination test was more sensitive of the two.

Animals↗