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排序方式: 共有158条查询结果,搜索用时 15 毫秒
101.
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Inhalt Die intramuskuläre Injektion des Depotgestagens Chlormadinonacetat in Kühe des 5. Zyklustages führte zu einer vorzeitigen Regression des periodischen Gelbkörpers. Corpora lutea coin 14. – 16. Zyklustag wares bei behandelten Kühen leichter, zeigten schwächere Steroiddehydrogenase-Aktivität, einen geringeren Anteil aktiver Luteinzellen in einem aufgelockerten Zellverband. Diese histologischen Veränderungen entsprachen Strukturen, wie sic in regressierenden Gelbkörpern unbehandelter Kühe gefunden werden. Contents (Premature regression of the Corpus luteum in cows following an injection of progestagen during early dioestrus) The i.m. injection of 30 mg Chlormadinonacetate (CAP) in cows on day 5 of their sexual cycle resulted in a premature regression of the corpus luteum. In treated animals C.L. of day 14 to 16 of the sexual cycle were 20 % lighter in weight, had less intensity of steroid dehydrogenase activity and showed fewer and disorderly distributed lutein cells. These histological and histochemical findings are similar to structures found in normal regressing C.L. 相似文献
103.
Von E. Schilling K. Wittenberg H. Maree J. Lederer 《Reproduction in domestic animals》1979,14(3):97-103
Inhalt: In Zusammenarbeit rnit 2 Besamungsstationen wurden Bullenejakulate nach Verdunnung mit 1 % Ascorbinsaure oder 1 n NaOH versetzt und auf pH-Werte von 5,9 -6,1 bzw. 7,5-7,7 eingestellt. Um die normale Befruchtungsfahigkeit des Spermas zu garantieren, wurden die Einwirkungszeiten bis zur Kiihlung rnit 30–45 min. relativ kurz gehalten. Es wurden Pellets und Minitiib-Pailletten rnit jeweits 30 Mill. Spermien hergestellt und tiefgefroren. Die Konzeptionsraten kzgen in allen Fallen uber den Stationsdurchschnitten. Durch Behandlung rnit NaOH wurde bei einem Charolaisbullen der schon hohe Anteil von 55,7 % mannlicher Nachkommen auf 57,5 % gesteigert. Von 3 Testbullen reagierte nur ein Bulle auf NaOH mit der Erhohung des Anteils mannlicher Kalber um 5 %, die beiden anderen Bullen reagierten auf diese Behandlung nicht. Der gfeiche positiv reagierende TestbulCe hatte nach Behandlung des Spermas mit Ascorbinsaure den Anteil weiblicher Kalber u m fast 10 % auf 60,1 % erhoht, fur die 3 Testbullen wurde mit dieser Verbindung ein statistisch signifikanter Anteil an weiblichen Kalbern von 55,8 % erzielt. Die Ursachen der betrachtlichen individuellen Reaktion sind noch nicht bekannt. 相似文献
104.
Contents Determination of the osmotic resistance of boar spermatozoa and the relations to sperm freezing and long storage The osmotic behaviour of fresh boar spermatozoa (482 ejaculates from 34 A.I. boars) was examined in a standard medium but with different osmotic pressures ranging from 150 mosm/kg till 500 mosm/kg. The percentage of spermatozoa with normal acrosomal ridge (NAR) was determined after incubation of 0.2 ml fresh semen in 3 ml of the osmotic test solutions at 39° C for 15 and 120 min. In the non-isotonic media % NAR decreased and could be quantified depending to incubation time and to the different osmolalities; NAR decreased strongest at 150 or 500 mosm/kg and after 120 min incubation time. Differences in % NAR were large between ejaculates and between boars but low within boars and statistically significant correlations had been found to % NAR and motility in froren/thawed semen samples or stored samples. Still higher correlations were found by calculation of an osmotic resistance test-value (ORT-value) which is defined as follows: ORT = 1/2 % NAR in isotonic medium/(after 15 min) +% NAR in 150 or 500 mosm/kg/(after 15 or 120 min) ORT-values can be calculated for hypotonic (150 mosm/kg) as well as for hypertonic (500 mosm/kg) test solutions and for 15 and 120 minutes incubation time. The hypotonic ORT-value for 120 min. is the most accurate; the values varied from 34 till 83 between ejaculates and from 44 till 76 between boars with a low variability within boars. Grouping of boars by their ORT-values in “good”, “moderate” and “poor” corresponded to a similar grouping of these boars by their semen quality (% NAR and motility) in preserved semen samples. Also a grouping of single ejaculates by their ORT-values corresponded to a similar qualitative classification of these ejaculates. ORT seems to become a good and practicable assessment test for the selection of boars suitable dor deep freezing or long storage of their spermatozoa. On the other hand preservation techniques too can be examined by ORT. But more investigations with this test must be done especially its relation to the fertilization capacity of semen samples with different ORT-values. 相似文献
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108.
Schilling JG 《Science (New York, N.Y.)》1969,165(3900):1357-1360
Abundance patterns of rare earths of submarine tholeiitic basalts from the axial trough of the Red Sea resemble those of basalts from mid-ocean ridges but are distinct from shield or plateau basalts of tholeiitic composition. These results imply that à similar magmatic process, related to spreading of sea floors, operates beneath the axial trough of the Red Sea and the crest of mid-ocean ridges. 相似文献
109.
Schilling G 《Science (New York, N.Y.)》2000,290(5493):926-927
Most astrophysicists puzzling over what causes gamma ray bursts--short, intense explosions of high-energy photons that occur deep in space--now agree that the answer is a hypernova, the blast of energy released when a supermassive star collapses into a black hole. Two papers in this issue of Science (pp. 953 and 955), reporting on new x-ray observations of two gamma ray bursts, argue that the hypernova model tells only half of the story. On its way to becoming a black hole, the authors propose, the supermassive star actually collapses twice. 相似文献
110.
Schilling G 《Science (New York, N.Y.)》2000,289(5476):29
Titanic explosions that emit powerful flashes of energetic gamma rays are one of astronomy's hottest mysteries. Now an analysis of the nearest gamma ray burst yet detected has added weight to the popular theory that they are expelled during the death throes of supermassive stars. 相似文献