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141.
Twelve strains of Yersinia enterocoliticaa and 4 strains of a Y. enterocolittica-like organism (Y. intermedia) were isolated from 374 pooled raw milk samples. Growth occurred in a cold enrichment system using phosphate buffer solution (7 strains), peptone solution (5 strains) and yeast extract—casein—cystine broth (5 strains) Serovar 13,7 was most frequently isolated (8 strains) followed by serovars 5,27 (2 strains), 6,31, 7,8, 14 and 22 (each one strain). Two strains were untypable, serologically. Seasonal variation was of little consequence, but the regional incidence was an important feature of the bacteriological findings. Autoagglutination tests gave negative results with all isolates. Although so-called “clinical strains” were not identified, the relationship of the strains of Yersinia to milk-borne infections in humans cannot be excluded. 相似文献
142.
143.
Characterization of myofibrillar adenosine triphosphatase activity and liberation of actin from myofibrils upon heating chicken breast meat 下载免费PDF全文
Masanori Matsuishi Yoshitaka Eda Emi Saito Shohei Yamamoto Kenji Kanamori Yuto Goto Yutaro Kobayashi Akihiro Okitani 《Animal Science Journal》2018,89(3):597-605
Denaturation of actin and myosin in myofibrils induced by heating at 50°C was investigated to reveal the mechanism of irreversible liberation of actin from myofibrils on heating at lower temperatures than conventional cooking. Denaturation of these proteins was determined by Mg2+‐ATPase (adenosine triphosphatase) and Ca2+‐ATPase activities. When minced meat was heated for 20 min, actin was liberated accompanying denaturation of 80% of actin and 50% of myosin. Heating of the myofibrillar fraction (MFF) isolated from meat homogenate induced much slower denaturation of actin than myosin. When MFF was heated with sarcoplasmic fractions, denaturation of actin was facilitated, suggesting that sarcoplasmic fractions contain factors to facilitate actin denaturation. Inosine‐5′‐monophosphate, a component of sarcoplasmic fractions, was shown to have no effect on actin and myosin denaturation. These results suggest that heating meat at 50°C dissociates binding (‘Bond A’) between actin and myosin participating in ATPase activities, resulting in denaturation of both proteins under influence of sarcoplasmic components. Although denaturation of actin and myosin disrupted Bond A, actin was not liberated simultaneously, suggesting the presence of another bond (‘Bond B’, more heat‐stable than Bond A) between both proteins and necessity of disruption of Bond B for actin release from myofibrils. 相似文献
144.
Randomized clinical trial to evaluate the effectiveness of enrofloxacin as a second‐line antibiotic for treatment of acute Escherichia coli mastitis 下载免费PDF全文
Kazuhiro Kawai Akira Takeda Michiaki Yamada Fumi Kayasaki Nao Kondo Yoshiko Sasaki Nahoko Kanai Takuma Mukai Naoki Sawaguchi Masaya Higuchi Haruka Kondo Kouki Sugimoto Akane Yasuda Aiko Watanabe 《Animal Science Journal》2018,89(7):1033-1039
The objective of the present study was to evaluate the effectiveness of enrofloxacin (ERFX) as a second‐line antibiotic for treatment of acute Escherichia coli (E. coli) mastitis. Forty‐two cows with naturally occurring acute E. coli mastitis were enrolled. On the first day of treatment (day 0), empirically selected antibiotics (oxytetracycline: n = 32, kanamycin: n = 10) were administered. Although systemic signs improved in 10 cows (first‐line group), the signs remained unchanged or worsened in 32 cows on day 1, including two cows that were found dead. The 30 surviving cows were randomly assigned to second‐line groups constituting an ERFX group (n = 19) or a control group (n = 11) that was treated with other antibiotics. Response to each treatment was evaluated by measuring clinical signs from day 0 to day 3, subsequent quarter milk recovery, and the 60‐day survival rate. Appetite on day 3 was significantly better in the ERFX group compared to the control group. No significant differences were observed in the 60‐day survival rate or the subsequent milk recovery between the ERFX group and the control group. Thus, the use of ERFX as a second‐line antibiotic for the treatment of acute E. coli mastitis could induce a rapid appetite recovery. 相似文献
145.
Photons are excellent information carriers but normally pass through each other without consequence. Engineered interactions between photons would enable applications as varied as quantum information processing and simulation of condensed matter systems. Using an ensemble of cold atoms strongly coupled to an optical cavity, we found that the transmission of light through a medium may be controlled with few photons and even by the electromagnetic vacuum field. The vacuum induces a group delay of 25 nanoseconds on the input optical pulse, corresponding to a light velocity of 1600 meters per second, and a transparency of 40% that increases to 80% when the cavity is filled with 10 photons. This strongly nonlinear effect provides prospects for advanced quantum devices such as photon number-state filters. 相似文献
146.
A rapid and efficient method for the regeneration of plantlets from root explants ofRobinia pseudoacacia L. by suspension culture was established. The roots taken from aseptically grown 15-day-old seedlings were used as explants.
It was determined that photoperiodicity was necessary for root proliferation, and that the promotive effect of IAA (3-indoleacetic
acid) on root proliferation was better than that of IBA (3-indolebutyric acid). The roots cultured in 1/2 MS liquid medium
containing 3 μM IAA and 1% sucrose at 25°C under 16-hour photoperiod with 50 μmol m−2s−1 PPFD (photosynthetic photon flux density) shaking at 100 times/min reciprocally showed high efficiency for root proliferation.
BAP (6-benzylaminopurine) was found to be essential to induce adventitious shoots from the roots, and the roots cultured in
the medium supplied with 3 μM BAP combined with 1–6 μM IAA for 3 weeks under the same conditions as in the root proliferation
period were most suitable for adventitious shoot inducement. 相似文献
147.
Thongphakdee A Kobayashi S Imai K Inaba Y Tasai M Tagami T Nirasawa K Nagai T Saito N Techakumphu M Takeda K 《The Journal of reproduction and development》2008,54(2):142-147
This study was conducted to investigate the developmental capacity of domestic cat-bovine reconstructed embryos via interspecies somatic cell nuclear transfer (iSCNT) and to observe the mitochondrial DNA (mtDNA) content of the iSCNT embryos. The iSCNT embryos were generated using mixed-breed domestic cat fibroblasts as donor cells and enucleated bovine oocytes as the recipient cytoplasm. When the developmental capacities of iSCNT embryos and parthenogenic bovine embryos were compared, there was no difference (P>0.05) in the rates of cleavage and development to the 8-cell stage (86.6 vs. 84.0% and 32.2 vs. 36.2%, respectively). However, in contrast to development of parthenogenic embryos to the morula and blastocyst stages, no iSCNT embryos (0/202) developed beyond the 8-cell stage. For mtDNA analysis, iSCNT embryos at the 1-cell, 2-cell, 4-cell and 8-cell stages were randomly selected. Both cat and bovine mtDNA quantification analysis were performed using quantitative PCR. The levels of both cat and bovine mtDNA in cat-bovine iSCNT embryos varied at each stage of development. The cat mtDNA concentration in the iSCNT embryos was stable from the 1-cell to 8-cell stages. The bovine mtDNA in the iSCNT embryos at the 8-cell stage was significantly lower than that at the 4-cell stage (P<0.05). No difference in the proportions of cat mtDNA in the iSCNT embryos was found in any of the observed developmental stages (1- through 8-cell stages). In conclusion, bovine cytoplasm supports domestic cat nucleus development through the 8-cell stage. The mtDNA genotype of domestic cat-bovine iSCNT embryos illustrates persistence of heteroplasmy, and the reduction in mtDNA content might reflect a developmental block at the 8-cell stage. 相似文献
148.
149.
Sang -Gyu Kim Kagayaki Morishima Nobukazu Satoh Takashi Fujioka Setsuo Saito Katsutoshi Arai 《Fisheries Science》2007,73(5):1087-1093
ABSTRACT: Five loci ( Phz2 , Phz6 , Phz7 , Phz12 , and Phz14 ) of microsatellite DNA markers developed in a previous study for parentage assignment in the hatchery population generated by mating among 61 broodstock fish (35 females and 26 males) in a spawning tank, were selected. After natural spawning in the same tank, larvae collected at three different times were categorized into early phase (EP), middle phase (MP), and late phase (LP) groups. In the parental broodstock, the mean number of alleles per locus was 21.8 and expected heterozygosity ( H E ) was 0.813. In the progeny, the mean number of alleles per locus decreased to 11.6 (EP), 14.4 (MP), and 6.4 (LP) and H E to 0.796 (EP), 0.833 (MP), and 0.681 (LP). Parental assignment determined eight dams and six sires as major parents for the EP group. In the MP group, 13 dams and ten sires genetically contributed to spawning, but only three dams and two sires were involved in LP group progeny. In the hatchery population produced from a limited number of parental fish such as the LP group, genetic variability was apparently decreased. 相似文献
150.
Summary The development of a microbial community on cellulose (cellophane film and filter paper) buried in waterlogged soil was observed under a microscope. Throughout the decomposition of the cellulose, the biomass, immobilized N, ATP and gas metabolism of the microbial community were examined. As cellulose decomposition progressed, a microbial succession was recognized. This succession was divided into two stages. In the first stage, a few types of cellulolytic microorganisms predominated on the cellulose. Vigorous decomposition of the cellulose was accompanied by a rapid increase in microbial biomass, and H2 was evolved from the microbial community on the cellulose. In the second stage, the rate of cellulose decomposition was slow. The cellulose remaining was thickly covered with various types of microoganisms. The H2 produced was consumed by the microorganisms closely adhering to the remaining cellulose. In addition, non-cellular organic N accumulated on the remaining cellulose. A large part of the microorganisms seemed to be dormant in this stage. The trends in this microbial succession were similar to those found in ecosystem successions. 相似文献