Theoretical investigation of the electronic structure, elastic, dynamic properties of intermetallic compound NiBe under pressure

From the beryllide group, NiBe is a hybrid material of CsCl (B2) type structure and presents a large range of stoichiometry. In this paper, we have studied the structural, electronic, elastic, and dynamic properties of NiBe intermetallic compound under pressure by performing ab initio density functional theory using the Cambridge Serial Total Energy Package (CASTEP). In B2 structure, we have obtained the lattice constant ($${A}_{\mathrm {0}}$$), equilibrium volume ($${V}_{\mathrm {0}}$$), bulk modulus ($${B}_{\mathrm {0}}$$) and its pressure derivative ($${B}_{0}$$ ’) and elastic constants. We have quantitatively analyzed the band structure and the corresponding density of states (DOS). We have also estimated the mechanical stability and brittle/ductile behaviors of this compound based on the computed elastic constants. It is found that this structure is stable between 0 and 50 GPa pressure for NiBe compound. Finally, the changing degree of anisotropy with pressure was analyzed in three and two dimensions

The effects of GnRH+PGF(2 alpha) and hCG+PGF(2 alpha) applications in postpartum dairy cows on oestrus syncronization and fertility

The aim of this study was to determine the effect of GnRH + PGF(2alpha) and hCG + PGF(2alpha) applications on oestrus and fertility in dairy cows postpartum between days 35 and 45. In this study, 117 healthy, 3-7-year-old Holstein dairy cows from the same farm under similar husbandry conditions were used and they were in postpartum days between 35 and 45. Cows were divided equally into three groups randomly. Group I (n = 39): on day 0, 2000 IU hCG IM (Pregnyl(R) Organon) was given, on day 7, 500 mug Cloprostenol Na IM (Estrumate(R), DIF), and on day 9, 12.6 mug Buserelin acetate IM (Receptal(R), Hoechst). Group 11 (n = 39): on day 0. 12.6 mug Buserelin acetate IM (Receptal(R), Hoechst) was given, on day 7, 500 mug Cloprostenol Na IM (Estrumate(R), DIF), and on day 9, 2000 IU hCG IM (Pregnyl(R), Organon). Group III (n = 39): they received 500 mug Cloprostenol IM (Estrumate(R), DIF) twice, at 11-d intervals. The diameters of the follicules in ovaria were measured in the cows in groups I and 11 on day 9, and in the cows in group 11148 h after the second Cloprostenol Na application, using transrectal ultrasonography. The cows in groups I and 11 were artificially inseminated 12 and 24 h after applications on day 9. The cows in group III were artificially inseminated 60 and 84 In after the second Cloprostenol application. On day 28 and day 55 after insemination, pregnancy was diagnosed using transrectal ultrasonography. No statistical differences were found between the cows in groups I and 11 and the cows in groups 11 and III in terms of dominant follicule, pregnancy and embryonic death on day 28 and day 55 (p > 0.01). The rates of pregnancy between groups I and III on day 28 and the cows in the same groups which have dominant follicule on day 28 and day 55 differ statistically, being positive for group I (p 0.01). In this study it was found that there were no statistical differences among the three groups in terms of showing oestrus and it was also found that application of GnRH, to stimulate ovulation, before insemination and pregnancy resulted in similar findings as hCG application. However, group I had higher pregnancy rates (statistically significant) than group 111, which did not receive hormones before insemination. These results indicate that it will be useful to apply GnRH before insemination to increase pregnancy rates

Studies on the in vitro maturation of cat oocytes

The aim of the present study was to investigate the effects of gonadotrophin and Bovine Serum Albumin (BSA) supplemented Synthetic Oviduct Fluid (SOF) and Ham's F-10 media on the in vitro maturation of cat oocytes. Cocytes collected from spayed stray queens served as the material of the study. The ovaries were brought to the laboratory within 2 h in PBS solution at 38 degreesC. Recovered oocytes were divided into two groups (Group 1: SOF + 0,4% BSA + 10 mug/ml FSH + 10 mug/ml LH, group 2: Ham's F-10 + 0,4% BSA + 10 mug/ml FSH + 10 mug/ml LH) and left for maturation in an incubator at 38.5 degreesC for 48 h under atmosphere containing 5% O-2, 5% CO2 and 90% N-2 and almost 100% humidity. Oocytes were then fixed and stained. The maturation status of the oocytes was evaluated under a phase-contrast microscope at x400 magnification. Data were compared by using Student's t-test. Group 1 had 209 oocytes and group 2 had 207: a total of 416. In group 1 54.06% (113/209) and in group 2 29.00% (60/207) of the oocytes reached the M II stage. The difference between these values was statistically significant. At the end of the study, it was concluded that SOF medium was superior to Ham's F-10 medium for the in vitro maturation of cat oocytes. These results also showed that a satisfactory background for in vitro fertilization studies of cat oocytes has been established

Use of Spermac (R) staining technique in the determination of acrosomal defects in cat semen

The types and rates of acrosome and other (head, mid-piece and tail) abnormal spermatozoon types were determined by the Spermac(R) staining technique

The effect of Gonadotrophins on estrus induction and fertility in prepubertal gilts

The aim of our study was to investigate the efficacy of exogenous gonadotrophin to induce puberty and pregnancy in prepubertal gilts which had reach the weight of fully grown pigs. The animals used in the study included 195 crossbreed German Landrace gilts aged between 150-180 days old, weighing between 75-90 kg and 24 crossbreed German Landrace adult male pigs. The prepubertal gilts of Group I (n = 65) and Group H (n = 65) were first administered with single IM dose of 1500 IU PMSG. At the same time, animals from the Group III (n = 65), which formed the control group, received 2 ml of a placebo. Seventy two hours after the PMSG administration, animals from the group I received IM 500 IU hCG while 8 mug of GnRH was given to die Group 11. Animals from the control group were administered at the same time with a placebo. Twenty four hours after hCG, GnRH placebo administrations, the gilts were exposed to the male pigs during 72 hours. Pregnancy diagnosis was performed by ultrasonic techniques between 35-45 days after mating. Estrus symptoms were recorded in 56 animals (86.2 %) from the Group 1, 4.2 +/- 0.4 days after the last administration the estrus was detected in 55 animals (84.6 %) from the Group H, 4.3 +/- 0.5 days after the end of the treatment. In the control group, 61 animals exhibited estrus behaviour spontaneously 48 : 10,4 days after the last placebo administration. Pregnancy was diagnosed in 53 animals of the Group 1 (81.5 %), 51 of the Group 11 (78.5 %) and 57 of the control group (87.7 %). The size of the first litter was a 7.8 +/- 1.3 in Group 1, 7.6 +/- 1.4 in Group II and 10.2 +/- 1.1 in the control group. It has been concluded that, a fertile estrus can be induced using exogenous gonadotrophins (PMSG and hCG) or a treatment associating PMSG with GnRH in prepubertal gilts and that these treatments improve lifetime reproductive performance

Effects of different maturation periods on in vitro maturation of bovine oocytes

Primer oocytes (n=157) collected from ovaries of slaughtered cows were matured at 39 degrees C with 95-100% humidity and under a gas mixture of 5% O-2 5% CO2 and 90% N-2 for 22 (n=52), 24 (n=52) and 26 (n=53) hours. Modified Parker's Medium (MPM) supplemented with FSH and 20% ECS was used as maturation medium. At the end of these periods all oocytes were fixated in ethanol:acetic acid in the ratio of 3:1 for 2A hours and stained by %2 aceto-orcein to evaluate the maturational criteria

Comparison of ovine spermatozoal morphological features after staining of fixation and assessment of morphological abnormalities in dead/live spermatozoa

The objectives of this study were to (i) compare the effects of two staining techniques and one fixative solution on the morphological features of ram spermatozoa and (ii) evaluate the morphological features of dead/live spermatozoa by using Eosin-Nigrosin staining. The morphological features of raw spermatozoa were evaluated (by Phase Contrast microscopy) after staining with Eosin-Nigrosin mixture or Nigrosin (alone), or after fixation with Hancock's buffered formol saline solution. 42 raw pooled semen samples from 6 Kivircik rams were used. The percentages of spermatozoa with abnormal acrosomes and total morphological abnormalities averaged 3.97% and 14.78% in Hancock's solution, compared with averages of 10.07% and 18.54%; 7.97% and 18.45% for smears stained with Eosin-Nigrosin or Nigrosin (alone), respectively (P<0.05). The percentages of the same features for dead spermatozoa averaged 15.38% and 24.42%, compared with averages of 4.21% and 10.80% for live spermatozoa, respectively (P<0.05)