排序方式: 共有52条查询结果,搜索用时 0 毫秒
11.
DN Basov SI Woods AS Katz EJ Singley RC Dynes M Xu DG Hinks CC Homes M Strongin 《Science (New York, N.Y.)》1999,283(5398):49-52
Analysis of the interlayer infrared conductivity of cuprate high-transition temperature superconductors reveals an anomalously large energy scale extending up to midinfrared frequencies that can be attributed to formation of the superconducting condensate. This unusual effect is observed in a va- riety of materials, including Tl2Ba2CuO6+x, La2-xSrxCuO4, and YBa2Cu3O6.6, which show an incoherent interlayer response in the normal state. Midinfrared range condensation was examined in the context of sum rules that can be formulated for the complex conductivity. One possible interpretation of these experiments is in terms of a kinetic energy change associated with the superconducting transition. 相似文献
12.
13.
We report the case of a bilateral and multilocular spermatocele and sperm granuloma in a dog that was vasectomized 5 years before. Clinical examination revealed scrotal dermatitis and benign prostatic hyperplasia. Orchiectomy was performed, and gross and histological examination showed testicular degeneration associated with epididymal sperm granuloma. In relation to this case, the literature about long-term effects of vasectomy in dogs has been reviewed. On the basis of these results, a preventive sonogram and physical assessment in prostate and other reproductive structures before vasectomy is recommended. 相似文献
14.
Oestrus Expression and Ovarian Function in Repeat Breeder Cows, Monitored by Ultrasonography and Progesterone Assay 总被引:1,自引:0,他引:1
Ovarian ultrasonography and plasma progesterone levels were monitored in 37 lactating Holstein cows with a history of repeat breeding; the data obtained were analysed in conjunction with clinical and behavioural signs, to identify the aetiology of the syndrome. Differences were detected between RBCs displaying apparently normal cycles and others with irregular cycles. There were also differences in heat expression; a large number of repeat breeder cows (RBCs, 50%) displayed delayed or silent oestrus. Ovarian disorders were common in RBCs, and included ovarian cysts, mistimed AI, subluteal progesterone levels, luteal dysfunction or ovulation defects. Both ultrasonography and plasma progesterone assays are useful tools for ascertaining the aetiology of the repeat breeder syndrome. 相似文献
15.
16.
17.
18.
Effect of oestrous synchrony between embryo donors and recipients,embryo quality and state on the pregnancy rate in beef cattle 下载免费PDF全文
MCC Rodrigues ALM Bonotto DAV Acosta AA Boligon MN Corrêa CC Brauner 《Reproduction in domestic animals》2018,53(1):152-156
This study aimed to evaluate the effect of oestrous synchrony between donors and recipients and the embryo quality on the pregnancy rate in beef cow recipients. The experiment was performed over two years at an embryo transfer (ET ) centre in Southern Brazil. Ninety Aberdeen Angus cows were subjected to superovulation (SOV ) protocols, resulting in the recovery of 1,048 transferable embryos. Eleven groups were formed with intervals of 6 hr, from ?30 to +30 hr, with respect to recipient versus donor oestrous detection. Evaluation of embryo quality was according to the IETS guidelines. The overall pregnancy rate was 52%. Effects related to donor and recipient oestrous synchronization on pregnancy rate were observed (p = .01), ranging from 36% to 50%. The embryo quality rate affected the pregnancy rate, where Grade I resulted in 57% and Grade III in 43% of pregnancy (p < .001). The embryonic state (frozen or fresh) showed no (p > .05) effect on pregnancy rate: 53% for fresh embryos and 44% for frozen embryos. The odds ratio for explanatory variables causing pregnancy indicated that Grade III embryos had 31% less chance of conception compared to Grade I. Thus, oestrous synchrony between donor and recipient, considering ±30 hr apart, can affect the pregnancy rate along with embryo quality. 相似文献
19.
CC Pérez‐Marín FD Requena A Arando L Requena F Requena EI Agüera 《Reproduction in domestic animals》2018,53(2):534-544
The aim of this study was to determine the effects of various abiotic factors, such as light, physical stress (pipetting) and thermal shock, on the quality of fresh and cooled equine sperm. In experiment I, four sperm aliquots were subjected to different light exposures: (i) protected control samples (CTRL), (ii) exposed to UV light at 10 cm (UV10), (iii) exposed to UV light at 20 cm (UV20) and (iv) exposed to laboratory lighting (LAB). In experiment II, four semen aliquots were subjected to repeated pipetting for 0, 10, 20 and 30 times (CTRL, P10, P20 and P30, respectively). In experiment III, four semen aliquots at 15°C were subjected to thermal oscillations: (i) cooled control sperm at 15°C (CTRL), (ii) oscillations of 1.9°C/min to a temperature of 30°C (T30), (iii) oscillations of 1.4°C/min, with the temperature rapidly falling until reaching 1.3°C (T0R) and (iv) oscillations of 1.1°C/min, with the temperature slowly falling until reaching 4.2°C (T0S). The results revealed that after 30 min, UV10 and UV20 sperm samples showed significantly (p < .05) lower total and progressive motility values, sperm kinematic parameters and mitochondrial potential. After 45 min of exposure, differences were highly significant (p < .001). No significant differences (p > .05) were found for pipetting or thermal oscillations. The results suggest that, even if equine sperm samples are not handled in the laboratory under optimal conditions, fresh and cooled equine spermatozoa are able to resist the impact of various abiotic stimuli without any reduction in their quality. This study analyses the effect on normospermic samples, but future research could look at the tolerance that asthenozoospermic equine samples have to these abiotic influences. 相似文献
20.
Brian P. Grossbard DVM Catherine A. Loughin DVM Diplomate ACVS ACCT Leonard J. Marino MD FAAP Joseph Sackman Scott E. Umbaugh BSE MSEE PhD Patrick S. Solt BSEE MSCS Jakia Afruz BSAPECE MSAPECE Peter Leando PhD DSc DAc Martin L. Lesser PhD EMT‐CC Meredith Akerman MS 《Veterinary surgery : VS》2014,43(7):869-876