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Melatonin reduces apoptotic cells,SOD2 and HSPB1 and improves the in vitro production and quality of bovine blastocysts 下载免费PDF全文
TC Marques EC da Silva Santos TO Diesel LO Leme CF Martins MAN Dode BG Alves FPH Costa EB de Oliveira ML Gambarini 《Reproduction in domestic animals》2018,53(1):226-236
Effects of adding different concentrations of melatonin (10?7, 10?9 and 10?11 M) to maturation (Experiment 1; Control, IVM + 10?7, IVM + 10?9, IVM + 10?11) and culture media (Experiment 2; Control, IVC + 10?7, IVC + 10?9, IVC + 10?11) were evaluated on in vitro bovine embryonic development. The optimal concentration of melatonin (10?9 M) from Experiments 1–2 was tested in both maturation and/or culture media of Experiment 3 (Control, IVM + 10?9, IVC + 10?9, IVM /IVC + 10?9). In Experiment 1, maturated oocytes from Control and IVM + 10?9 treatments showed increased glutathione content, mitochondrial membrane potential and percentage of Grade I blastocysts (40.6% and 43%, respectively). In Experiment 2, an increase in the percentage of Grade I blastocysts was detected in IVC + 10?7 (43.5%; 56.7%) and IVC + 10?9 (47.4%; 57.4%). Moreover, a lower number and percentage of apoptotic cells in blastocysts were observed in the IVC + 10?9 group compared to Control (3.8 ± 0.6; 3.6% versus 6.1 ± 0.6; 5.3%). In Experiment 3, the IVC + 10?9 treatment increased percentage of Grade I blastocysts with a lower number of apoptotic cells compared to IVM /IVC + 10?9 group (52.6%; 3.0 ± 0.5 versus 46.0%; 5.4 ± 1.0). The IVC + 10?9 treatment also had a higher mRNA expression of antioxidant gene (SOD 2) compared to the Control, as well as the heat shock protein (HSPB 1) compared to the IVM + 10?9. Reactive oxygen species production was greater in the IVM /IVC + 10?9 treatment group. In conclusion, the 10?9 M concentration of melatonin and the in vitro production phase in which it is used directly affected embryonic development and quality. 相似文献
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Objective: Mechanical evaluation of 2 suture constructs for extracapsular stifle stabilization. Study Design: In vitro study. Sample Population: Crimped interlocking loop constructs (ILC) of 45 kg nylon leader line (NLL) and Orthofiber® (OF). Methods: ILC were tightened to 100 N, then crimp secured. Ramp to failure (n=10/group)—Data were derived from force/displacement plots. Stress–relaxation testing (n=10/group)—ILC's were nondestructively loaded and held at resultant displacement as force data were recorded. Incremental, cyclic loading (n=10/group)—ILC's were loaded (5 cycles/set) starting at 100 N and incrementally increased by 50 N (1 and 3 Hz protocols). Loop tension and elongation were recorded after each set. Results: Ramp to failure—initial loop tension was similar (NLL 75.5 ± 9.5 N; OF 68.7 ± 10.4 N, P=.140). Tested OF constructs were stiffer (NLL 125.7 ± 4.0; OF 234.6 ± 25.0 N/mm, P≤.001), had lower yield load (NLL 193.6 ± 13.8; OF 137.3 ± 94.3 N, P≤.001), lower peak load (NLL 873.7 ± 68.6; OF 653.6 ± 80.2 N, P≤.001), and lower elongation at failure (NLL 19.1 ± 1.4; OF 5.2 ± 1.0 mm, P≤.001) and at yield (NLL 1.52 ± 0.2; OF 0.3 ± 0.6 mm, P=.003) than NLL constructs. Yield in NLL ILC's was variable knot tightening/crimp slippage, but only crimp‐suture slippage in OF. Stress–relaxation testing—OF demonstrated greater relaxation. Incremental, cyclic loading—induced ILC elongation and tension loss in both groups, independent of loading frequency. NLL lost tension at lower rate, but elongated more than OF. Conclusions: NLL construct is mechanically superior to OF construct. 相似文献
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Average length of gestation on the dog is 63 ± 2 days but may vary between 57-71 days due to the long period of receptivity at oestrus and the extended period of sperm survival in the female genital tract. In contrast to other domestic animals progesterone- and oestrogen concentrations are almost identical in pregnant and non pregnant bitches, except for their rapid decline immediately prior to parturition. Control of luteolysis still poorly understood. Experiments with indomethacin leading to a blockade of the prepartal PgF2α increase, which commences with the decrease of progesterone, point toward a role of PgF2α at this stage of pregnancy, which was extended for several days. At physiological conditions first visible signs of parturition were observed at peak-PgF2α levels, 33.6 ± 17.6 hours after onset of luteolysis, which lasted over 16.8 ± 3.4 hours. Pulse-type releases of oxytocin were only observed after this point of time. To test for the effect of progesterone-withdrawal, four 51-57 days pregnant bitches were treated with the antiprogestin RU 38486 which inhibits the activity of progesterone at the receptor level. In all dogs first visible signs of parturition were observed 33.5 ± 7.5 hours after onset of treatment. However, the process of parturition came to an end after cervical opening and totally only one puppy was born. Different to a normal parturition no increase of PgF2α was observed. Relaxin levels were not influenced by treatment. These observations suggested that treatment with antiprogestin followed by PgF2α might be an adequate method to induce parturition in the dog; first experiences seem to confirm this conclusion. 相似文献
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DJ Leatherman SA Valdez BG Grant JC Cannon 《Journal of Equine Veterinary Science》1999,19(12):776, 778
Protein fractions of cerebral spinal fluid samples were analyzed in an effort to find a reliable, minimally invasive and cost effective method of diagnosing cervical vertebral myelopathy. There were six separate protein fractions analyzed by electrophoresis. In this study we specifically looked for a post beta spike in horses with spinal cord compression. There was no correlation in our study between horses with a post beta spike and CVM as diagnosed by a myelogram. 相似文献
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Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby 总被引:1,自引:0,他引:1
DK Yeomans J Barriot DW Dunham RW Farquhar JD Giorgini CE Helfrich AS Konopliv JV McAdams JK Miller WM Owen DJ Scheeres SP Synnott BG Williams 《Science (New York, N.Y.)》1997,278(5346):2106-2109
The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter. 相似文献
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Paolo Vassallo Chiara Marini Chiara Paoli Michela Bellingeri Frank Dhermain Silvio Nuti Sabina Airoldi Patrizia Bonelli Sophie laran Marie C. Santoni Guido Gnone 《水产资源保护:海洋与淡水生态系统》2020,30(8):1689-1701
- Geospatial models are used to predict the distribution of terrestrial and marine species, according to their ecological and ethological habits. The bottlenose dolphin is a cosmopolitan marine top predator, inhabiting most of the ocean, with the exception of polar and subpolar waters. This wide distribution is associated with a remarkable plasticity in ecological and behavioural habits, which makes it difficult to model and predict its distribution.
- This study proposes a ‘multi‐type approach’ to predict the presence and distribution of the bottlenose dolphin in the Pelagos Sanctuary, a Specially Protected Area of Mediterranean Importance located in the north‐west Mediterranean Sea. A multi‐type model based on random forest regression was developed, analysing the distribution habits of two geographical units living in the Pelagos area.
- When compared with a classical single‐type model, the multi‐type model performed much better in a prediction test (true skill statistics, TSS = 85% vs. 52%), confirming the value of this experimental approach. This work suggests that wild species should not be considered as one single‐type entity, as local specialization may change and shape their distribution habits.