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101.
Storage of buffalo (Bubalus bubalis) semen   总被引:1,自引:0,他引:1  
Characteristics of buffalo semen, diluents used for liquid storage, aspects involved in freezing and thawing of semen are reviewed, and fertility results after artificial insemination (AI) with frozen-thawed semen are given.  相似文献   
102.
 Long-term co-evolution of male's sexual extravagance and female's preference for it is studied. Fisher's ``Sexy Son' principle is checked against Zahavi's Handicap Principle. It is shown that although both principles are equally likely to explain this sort of co-evolution in the short run, only the second one allows for a long-term evolutionarily stable females' preference for costly male's extravagance. It is shown, however, that Fisher's argument, although not sufficient on its own to explain long-term persistence of females' choice, may tacitly appear as an indispensable component for the application of Zahavi's theory to the important case of dense polygenous populations. Received: 7 March 2001 / Revised version: 15 November 2001 / Published online: 26 June 2002  相似文献   
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Proper design of fermentation facilities and equipment modification can control the risks associated with largescale production and purification of microbially produced cytotoxic agents and oncogenic viruses. The primary biohazard risks to operators and the environment are generation of aerosols and accidental spills. Fermentation and recovery facilities can be constructed to contain these agents by installing fermentation equipment within a HEPA-filter-exhausted biological barrier. Within this barrier system, large-scale processing that generates potentially hazaradous areosols (filtration, centrifugation of transformed cells or crystal slurries, and banding of viruses) should be isolated from other operations. Isolation of equipment is often required, with provision for both chemical and biological decontamination of process wastes. Failsafe fermentor over-pressure sensors, parallel exhaust gas filtration, welded transfer lines, and modified sampling systems for elimination of aerosols can be installed on most fermentation equipment. Aerosol and spill containment by proper equipment design, coupled with appropriate personnel protective equipment and medical monitoring, make possible safe production of experimental growth factors and viruses from large-scale culture of transformed mammalian cells and production of cytotoxic antitumor antibiotics.  相似文献   
105.
Formaldehyde used for the disinfection of a laminar-flow biological safety cabinet was oxidatively degraded by using a catalyst. This technique reduced the formaldehyde concentration in the cabinet from about 5,000 to about 45 mg/m3 in 8 h. This technique should prove useful in other applications.  相似文献   
106.
Hepatocellular carcinoma (HCC) is rare in New World primates. We report the gross, microscopical, and immunocytochemical features of a spontaneous HCC in a free‐living marmoset (Callithrix sp.). Hepatitis B and C virus and aflatoxin immunohistochemistry were negative; however, concomitant intra‐ and extrahepatic biliary trematodiasis could have played a role.  相似文献   
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Summary. For-Met-βAlaψ[CSNH]-Phe-OMe (3), For-Met-βAlaψ[CH2NH]-Phe-OMe (5), For-Met-NH-pC6H4-SO2-Phe-OMe (8a), For-Met-NH-mC6H4-SO2-Phe-OMe (8b) and the corresponding N-Boc precursors (2, 4, 7a, b) have been synthesized and their activity towards human neutrophils has been evaluated in comparison with that shown by the reference tripeptide For-Met-Leu-Phe-OMe (fMLF-OMe). Chemotaxis, lysozyme release and superoxide anion production have been measured. 1H NMR titration experiments and IR spectra have been discussed in order to ascertain the preferred solution conformation adopted by the tripeptide 3 with particular reference to the presence of a folded conformation centred at the centrally positioned thionated β-residue.  相似文献   
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A radioecological survey in Antarctica shows that the239+240Pu,238Pu,241Am,90Sr, and137Cs activities were detectable in nearly all the samples. The activity level of239+240Pu,241Am, and137Cs in antarctic sediments was about 5–20 times lower than in the northern Adriatic Sea sediments, but the238Pu activities were relatively high. It was interesting to note that the90Sr concentrations in all the sediments tended to be low, which could be the result of the easier exchangeable behavior of90Sr in water. High concentrations were detected in mosses and lichens and their activity levels were comparable to those in central Italy. The radionuclide ratio analyses show that the major part of239+240Pu,241Am,90Sr, and137Cs was a result of nuclear weapon tests. The higher241Am/239+240Pu ratio was observed and it could perhaps be the result of fallout of nuclear weapon tests prior to 1962. The238Pu/239+240Pu ratio in the antarctic matrices was about seven times higher than in the Northern hemisphere and it could be inferred that the major part of238Pu was originating from the SNAP-9A satellite accident.  相似文献   
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