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Fall-calving Angus cows were used to evaluate the effect of ambient temperature on duration of gestation. In Exp. 1, cows were AI and calved in August (n = 14) or October (n = 10). Cows grazed native prairie pasture in Oklahoma and had a BCS of 6.0 ± 0.5 (1 = emaciated, and 9 = obese) at parturition. Commencing 2 wk before the expected calving date, blood samples were taken from the coccygeal vein every 2 to 3 d until calving. Cows that calved in August tended to have shorter gestations (P = 0.07) compared with cows that calved in October. Maximum daily ambient temperature during the last 14 d of gestation was greater for August-calving cows (P < 0.001) compared with October cows. Concentrations of cortisol in plasma during the last 4 d of gestation were greater in cows that calved in August (P < 0.04) compared with cows that calved in October. In Exp. 2, cows were AI and calved in either mid-August (n = 7), late-August (n = 6), September (n = 6), or October (n = 8) to evaluate the effects of elevated ambient temperature on duration of gestation, ruminal temperature at parturition, and plasma cortisol, progesterone, and estradiol. Temperature boluses (SmartStock, LLC, Pawnee, OK) programmed to transmit temperature every hour were place in the rumen at 255 d of gestation. Cows grazed native prairie pasture in Oklahoma and had a BCS of 6.5 ± 0.4 at calving. Maximum ambient temperatures during d 263 to 273 of gestation were influenced by month of calving × day (P < 0.001). Duration of gestation was shorter for mid-August cows (P < 0.05) compared with October cows, but did not differ compared with late-August (P = 0.29) and September (P = 0.50) cows. Ruminal temperature during the 4 d before calving was not influenced by month of calving (P = 0.76). Ruminal temperature was decreased during the 24 h before parturition for cows in all months (P < 0.01) compared with 2 to 4 d before parturition. Concentrations of cortisol in plasma during d 271 to 276 of gestation were less (P < 0.05) for late-August compared with cows that calved during the other months. Concentrations of progesterone were greater during 7 d before parturition in October compared with cows that calved in September. Estradiol in plasma of cows during late gestation was not affected by month of calving (P = 0.76). Exposure of beef cows to elevated ambient temperature resulted in shorter gestations. Ruminal temperature in cows decreased ≥ 0.3°C the day before parturition.

Gestating Angus, nonlactating, spring-calving cows were used to determine variation in maintenance energy requirements (MR); to evaluate the relationship among MR and cow and calf performance, plasma concentrations of IGF-I, T4, glucose, insulin, and ruminal temperature; and to describe the LM proteome and evaluate protein abundance in cows with different MR. Cows (4 to 7 yr of age) with a BCS of 5.0 ± 0.2 and BW of 582 ± 37 kg in the second to third trimester of gestation were studied in 3 trials (trial 1, n = 23; trial 2, n = 32; trial 3, n = 38). Cows were individually fed a complete diet in amounts to meet predicted MR (Level 1 Model of NRC), and feed intake was adjusted weekly until constant BW was achieved for at least 21 d (maintenance). Cows were classified on the basis of MR as low (>0.5 SD less than mean, LMR), moderate (±0.5 SD of mean, MMR), or high (>0.5 SD more than mean, HMR) MR. Blood samples were taken at maintenance and at 2 mo postpartum in trial 2. Muscle biopsies were taken from LMR and HMR after cows consumed actual MR for 28 d (trial 2) or 21 d (trial 3). Proteins from LM were separated by 2-dimensional difference gel electrophoresis and were identified, and abundance was quantified and compared. The greatest differences in MR between cows were 29%, 24%, and 25% in trials 1, 2, and 3, respectively. Daily MR (NEm, kcal·BW(-0.75)·d(-1)) averaged 89.2 ± 6.3, 93.0 ± 4.9, and 90.4 ± 4.6 in trials 1, 2, and 3, respectively. Postpartum BW and BCS, calf birth and weaning weights, postpartum luteal activity, and ruminal temperature were not influenced by MR of the cows. Concentrations of IGF-I were greater (P = 0.001) in plasma of MMR compared with LMR cows consuming predicted MR diets, and MR was negatively correlated with concentrations of IGF-I in plasma (r = -0.38; P = 0.05) at 2 mo postpartum. A total of 103 proteins were isolated from LM; 52 gene products were identified. Abundance of specific proteins in the LM was not influenced (P > 0.11) by MR. Variation in MR of cows will make it possible to improve feed efficiency by selection. Identification of biomarkers for MR will allow selection of more efficient cows, which consume less feed and produce calves with similar weaning weights. Productive cows that require less feed for maintenance will improve efficiency of production and enhance sustainability of the environment.

An understanding of the phase stability of AlF3 surfaces as a function of their environment is an important prerequisite in the development of, and an ability to control, their catalytic properties. In this study, all electron hybrid-exchange density functional theory is used to calculate the structure and corresponding energies of several α-AlF3 surfaces. It is shown that the surfaces expose under-coordinated Al ions that are potential Lewis acid sites. The binding energy of NH3 to these sites is calculated and used to quantify their relative acidities. The Lewis acid sites are significantly weaker than the strongest sites predicted to occur on β-AlF3 surfaces. The equilibrium morphology of α-AlF3 crystallites is predicted from the construction of an approximate Wulff plot. The stabilities of two representative terminations of α-AlF3, as a function of HF and H2O chemical potentials are computed using ab initio thermodynamics. The geometries of their stable surfaces are found to be strongly dependent on t...

First principles simulations of steps on the β-AlF3 (100) surface between two, previously identified, low-energy terminations have been performed. The optimization of these structures leads to the formation of microfacets having the (010) orientation. The microfaceted surface is found to have a lower surface energy than either of the low-energy terminations used to construct the model stepped system. This suggests that the (100) surface is not, thermodynamically, the most stable termination of β-AlF3. We have therefore also investigated the structure and stability of the (010) and (001) surfaces and find that both of these surfaces are lower in energy than the (100) surfaces. The surface energies of these planes are used to construct an approximate Wulff plot and thus predict the equilibrium crystal morphology.

Thermodynamic calculations based on hybrid-exchange density functional theory are used to predict the surface structure and stability of α-AlF3 ( 0 1 1 ¯ 2 ) in the presence of gaseous HF and H2O environments. The clean stoichiometric α-AlF3 ( 0 1 1 ¯ 2 ) is predicted to be Lewis acidic. However, under most reaction conditions this surface is unstable with respect to the adsorption of hydroxyl ions. This is consistent with experimental observations. It is predicted that the surface containing no hydroxyl ions could only be realised at high temperatures and under unrealistically dry conditions.

The vibrational modes of three solid AlF3 phases (alpha, beta, and amorphous high surface area AlF3) are investigated. Calculations have been performed using hybrid exchange correlation functionals to determine the equilibrium geometries and Gamma-point phonon frequencies for the alpha-AlF3 and beta-AlF3 phases. The calculated optical modes are in excellent agreement with experiment. The IR absorption of the amorphous, glasslike high surface area (HS)-AlF3 is also discussed. Deconvolution of the broad envelope of IR stretches and bending vibrations identifies the components of the observed broad band. From the IR vibrational spectrum it has been shown that both short-range and medium-range disorder are present within HS-AlF3. Structural phase transitions are identified by their phase transition temperature Tc, measured by thermal analysis.

Aluminum chloride is used extensively as Lewis acid catalyst in a variety of industrial processes, including Friedel-Crafts and Cl/F exchange reactions. There is a common misconception that pure AlCl3 is itself a Lewis acid. In the current study, we use experimental and computational methods to investigate the surface structure and catalytic properties of solid AlCl3. The catalytic activity of AlCl3 for two halide isomerization reactions is studied and compared with different AlF3 phases. It is shown that pure solid AlCl3 does not catalyze these reactions. The (001) surface of crystalline AlCl(3) is the natural cleavage plane and its structure is predicted via first principles calculations. The chlorine ions in the outermost layer of the material mask the Al3+ ions from the external gas phase. Hence, the experimentally found catalytic properties of pure solid AlCl3 are supported by the predicted surface structure of AlCl3.

Strong Lewis acid catalysts are widely used in a variety of industrial processes including Cl/F exchange reactions. Aluminum fluorides (AlF3) have great potential for use in such reactions. Despite the importance of the surface in the catalytic process little is known about the detailed atomic scale structure of AlF3 surfaces. In the current study we employ state of the art surface thermodynamics calculations based on hybrid-exchange density functional theory to predict the composition and structure of the basal plane surface of alpha-AlF3 for the first time. We examine four possible terminations of the alpha-AlF3 (0001) surface and demonstrate that the surface is terminated by a layer containing two fluorine atoms per cell at all realistic fluorine partial pressures. The fluorine ions in the outermost layer of the material reconstruct to mask the Al3+ ion from the external gas phase and consequently we would expect this surface to be inactive as a Lewis acid catalyst in line with experimental observation.

Fall-calving Angus cows were used to evaluate the effect of ambient temperature on duration of gestation. In Exp. 1, cows were AI and calved in August (n = 14) or October (n = 10). Cows grazed native prairie pasture in Oklahoma and had a BCS of 6.0 ± 0.5 (1 = emaciated, and 9 = obese) at parturition. Commencing 2 wk before the expected calving date, blood samples were taken from the coccygeal vein every 2 to 3 d until calving. Cows that calved in August tended to have shorter gestations (P = 0.07) compared with cows that calved in October. Maximum daily ambient temperature during the last 14 d of gestation was greater for August-calving cows (P0.001) compared with October cows. Concentrations of cortisol in plasma during the last 4 d of gestation were greater in cows that calved in August (P0.04) compared with cows that calved in October. In Exp. 2, cows were AI and calved in either mid-August (n = 7), late-August (n = 6), September (n = 6), or October (n = 8) to evaluate the effects of elevated ambient temperature on duration of gestation, ruminal temperature at parturition, and plasma cortisol, progesterone, and estradiol. Temperature boluses (SmartStock, LLC, Pawnee, OK) programmed to transmit temperature every hour were place in the rumen at 255 d of gestation. Cows grazed native prairie pasture in Oklahoma and had a BCS of 6.5 ± 0.4 at calving. Maximum ambient temperatures during d 263 to 273 of gestation were influenced by month of calving × day (P0.001). Duration of gestation was shorter for mid-August cows (P0.05) compared with October cows, but did not differ compared with late-August (P = 0.29) and September (P = 0.50) cows. Ruminal temperature during the 4 d before calving was not influenced by month of calving (P = 0.76). Ruminal temperature was decreased during the 24 h before parturition for cows in all months (P0.01) compared with 2 to 4 d before parturition. Concentrations of cortisol in plasma during d 271 to 276 of gestation were less (P0.05) for late-August compared with cows that calved during the other months. Concentrations of progesterone were greater during 7 d before parturition in October compared with cows that calved in September. Estradiol in plasma of cows during late gestation was not affected by month of calving (P = 0.76). Exposure of beef cows to elevated ambient temperature resulted in shorter gestations. Ruminal temperature in cows decreased ≥ 0.3°C the day before parturition.

Gestating Angus, nonlactating, spring-calving cows were used to determine variation in maintenance energy requirements (MR); to evaluate the relationship among MR and cow and calf performance, plasma concentrations of IGF-I, T4, glucose, insulin, and ruminal temperature; and to describe the LM proteome and evaluate protein abundance in cows with different MR. Cows (4 to 7 yr of age) with a BCS of 5.0 ± 0.2 and BW of 582 ± 37 kg in the second to third trimester of gestation were studied in 3 trials (trial 1, n = 23; trial 2, n = 32; trial 3, n = 38). Cows were individually fed a complete diet in amounts to meet predicted MR (Level 1 Model of NRC), and feed intake was adjusted weekly until constant BW was achieved for at least 21 d (maintenance). Cows were classified on the basis of MR as low (0.5 SD less than mean, LMR), moderate (±0.5 SD of mean, MMR), or high (0.5 SD more than mean, HMR) MR. Blood samples were taken at maintenance and at 2 mo postpartum in trial 2. Muscle biopsies were taken from LMR and HMR after cows consumed actual MR for 28 d (trial 2) or 21 d (trial 3). Proteins from LM were separated by 2-dimensional difference gel electrophoresis and were identified, and abundance was quantified and compared. The greatest differences in MR between cows were 29%, 24%, and 25% in trials 1, 2, and 3, respectively. Daily MR (NEm, kcal·BW(-0.75)·d(-1)) averaged 89.2 ± 6.3, 93.0 ± 4.9, and 90.4 ± 4.6 in trials 1, 2, and 3, respectively. Postpartum BW and BCS, calf birth and weaning weights, postpartum luteal activity, and ruminal temperature were not influenced by MR of the cows. Concentrations of IGF-I were greater (P = 0.001) in plasma of MMR compared with LMR cows consuming predicted MR diets, and MR was negatively correlated with concentrations of IGF-I in plasma (r = -0.38; P = 0.05) at 2 mo postpartum. A total of 103 proteins were isolated from LM; 52 gene products were identified. Abundance of specific proteins in the LM was not influenced (P0.11) by MR. Variation in MR of cows will make it possible to improve feed efficiency by selection. Identification of biomarkers for MR will allow selection of more efficient cows, which consume less feed and produce calves with similar weaning weights. Productive cows that require less feed for maintenance will improve efficiency of production and enhance sustainability of the environment.

CRYSTAL is an ab initio electronic structure program, based on the linear combination of atomic orbitals, for periodic systems. This paper concerns the ability of CRYSTAL to exploit massively parallel computer hardware. A brief review of the theory, numerical implementations and parallel solutions will be given and some of the functionalities and capabilities highlighted. Some features that are unique to CRYSTAL will be described and development plans outlined.

Juvenile granulosa cell tumor of the ovary occurs most frequently in young women and children. Ten percent of cases present during pregnancy. The majority of tumors are in FIGO Stage I and have a favorable prognosis. The prognosis of higher stage tumors, however, is generally less favorable. We report the long-term, disease-free survival of a patient with FIGO Stage III juvenile granulosa cell tumor of the ovary. We believe this to be the first report of a successful pregnancy following "MAC" chemotherapy for this particular malignancy.

Hybrid density-functional theory has been used to study phase stability and defect formation in the CuGaS2 chalcopyrite. The equilibrium population of intrinsic defects is predicted and it is shown that the material is intrinsically p-type doped. Extrinsic defects consisting of elements from group II, group IV, and group VII of the periodic table are studied. It is predicted that n-type doping of CuGaS2 is not possible through the addition of these extrinsic defects. The stability of the ordered defect compounds CuGa3S5 and CuGa5S8 is also investigated. These compounds are shown to be stable only in a very narrow region of phase space.

Hybrid exchange density functional theory is used to model defects on the beta-AlF(3) (100) surface. The stability of the surface with respect to the diffusion of surface F ions is investigated. It is shown that under typical reaction conditions (600 K) the surface is not kinetically hindered from reaching thermodynamic equilibrium. A reaction mechanism for the catalysis of 2CCl(2)F(2)--CClF(3) + CCl(3)F is proposed. The mechanism and corresponding reaction barriers are calculated using a double-ended transition state search method. It is predicted that the processes that determine the overall reaction rate occur at defect sites.

The current study employs hybrid-exchange density functional theory to investigate the adsorption of HF and HCl to under-coordinated Al ions on the beta-AlF(3) (100) surface. It is shown that the geometries of the adsorbates are strongly dependent on coverage. Furthermore, the adsorption of HCl leads to a number of distinct structures that have very similar energies. It is proposed that this result may explain the high catalytic activity of aluminium fluoride and aluminium chloro-fluoride surfaces towards chlorine-fluorine exchange reactions. The stretching and bending frequencies of the H-F and H-Cl bonds at half and full monolayer coverage are also calculated and the vibrational spectrum is found to be strongly dependent on the adsorption site and the coverage. The vibrational frequency shifts provide, therefore, a mechanism for experimentally characterising these surfaces.

In vitro maturation (IVM) is a reproductive technique critical to in vitro embryo production (IVP). Currently, IVP has low efficiency due to an inadequate IVM system where premature meiotic resumption results in low oocyte viability. Meiotic arrest is regulated primarily by 3′,5′-cyclic adenosine monophosphate (cAMP). Some successful methods of improving IVM have utilised cAMP modulators to maintain high intraoocyte cAMP, delaying the onset of nuclear maturation and allowing cytoplasmic maturation to occur. The current experiment is a follow-up to previous work in which an extended 2-step maturation system was examined. In the previous experiments, we found that meiotic resumption was significantly delayed, but the overall maturation rates of extended IVM were about half those of standard IVM, suggesting that the effects of the modulators on the oocytes were not completely reversible. The current experiment compares cAMP concentrations of oocytes in this extended IVM to standard IVM to determine whether high cAMP is the cause of the low maturation rate. Bovine oocytes (n = 686) were obtained from mixed-breed cattle by transvaginal ultrasound-guided aspiration. Oocytes from each cow were divided into 2 groups: standard IVM and extended IVM. Standard IVM consists of a 23-h maturation composed of TCM-199 supplemented with 10% fetal bovine serum, sodium pyruvate, pen/strep, glutamine, and FSH, and cultured at 39°C in 5% CO2. Extended IVM consists of 2 steps: a pre-IVM phase composed of HEPES-TALP supplemented with 100 µM forskolin (FSK) and 500 µM 3-isobutyl-1-methylxanthine (IBMX) for 2 h at 39°C, followed by an extended IVM phase composed of standard IVM media supplemented with 20 µM cilostamide for 31 h (39°C, 5% CO2). Additionally, oocytes in the extended IVM treatment group where held in HEPES-TALP media with FSK and IBMX during the 2-h oocyte collection period in order to prevent any decrease in cAMP before the oocytes could be placed in the extended IVM media. Oocytes in standard IVM were sampled at 0, 8, and 23 h of maturation, while oocytes in extended IVM were sampled at 0, 8, 18, and 33 h of maturation. Cumulus cells were removed from all oocytes by vortexing in hyaluronidase solution. Oocytes were stored in groups of 10 at –80°C. A cAMP enzyme immunoassay (GE Healthcare) was performed to determine cAMP concentrations throughout standard and extended IVM. Assay results were analysed using an ANOVA followed by a Tukey's pairwise test (Sigma Stat 3.5) to detect significant differences (P

Reduced tolerance to chilling and cryotolerance of oocytes and embryos has been associated with greater cytoplasmic lipids. Previous studies in the cow have demonstrated nutrition-induced modification of follicular components. trans-10, cis-12 conjugated linoleic acid (CLA) was identified as a potent inhibitor of milk fat synthesis in lactating cows, and inclusion of CLA in bovine embryo culture medium reduced embryo lipid content and improved post-thaw embryo survival. Dietary supplementation of cows with CLA could alter oocyte fatty acid metabolism, oocyte lipid composition, and embryo cryotolerance, and responses may be different between Bos indicus and Bos taurus cattle. Therefore, a series of experiments were conducted to evaluate effects of dietary CLA on bovine oocyte lipid content and lipid metabolism and cryosurvival of in vitro-produced embryos from CLA-supplemented oocyte donor cows. Lactating Holstein cows (n = 39) were supplemented 100 g per head/d CLA or Ca salts of palm oil to determine effects of dietary CLA on milk production and milk composition. Nonlactating Holstein (n = 8) and Brahman (n = 17) cows were individually supplemented with 150 g per head/d CLA or no lipid supplement. Cumulus-oocyte complexes (COC) were collected after 41 ± 1 day of CLA supplementation, and mRNA was isolated for qPCR. Relative gene expression in COC from CLA- and control-fed cows was evaluated for genes involved in lipid metabolism (CPT1, FADS2, and PPARα). Crossbred (Angus × Red Angus × Brangus) cows (n = 28) were randomly allotted to a 2 × 2 factorial experiment and fed 150 g per head/d CLA or no lipid supplement. Oocytes were collected (Day 129 and 143 of CLA supplementation), matured, fertilized, and cultured in vitro for 7 days in serum-free culture medium. Embryos were cryopreserved in individual 0.25-mL plastic straws containing 1.5 M ethylene glycol using a slow-cooled method. Post-thaw survival and hatching were evaluated using a 24-h in vitro culture (mSOF with 5% FBS) assay. Milk yield, milk composition, and Nile Red intensity were analysed using the GLM procedure of SAS (SAS Institute Inc., Cary, NC, USA). Follicle and oocyte responses were analysed with the Mixed procedure of SAS. Relative gene expression of COC was evaluated using the REST 2009 Software. In vitro embryo production, post-thaw survival, and hatching rates were analysed using Chi Square. Milk fat was depressed (P

The aim of this study was to determine the risk of malignancy in cystic ovarian tumors10 cm in diameter in asymptomatic postmenopausal women or womenor =50 years of age.All cystic ovarian tumors detected by transvaginal sonography screening in asymptomatic postmenopausal women or womenor =50 years of age were evaluated with respect to size and morphology. Histology was recorded on all tumors removed surgically. Follow-up data were available both on patients undergoing surgery and on those who elected to be followed without operative intervention.Unilocular cystic tumors were detected in 256 of 7705 patients (3.3%). All tumors were10 cm in diameter and 90% were5 cm in diameter. One hundred twenty-five of these cysts (49%) resolved spontaneously within 60 days and 131 (51%) persisted. Forty-five patients with persisting ovarian cysts underwent operative removal of these tumors. Thirty-two patients had ovarian serous cystadenomas, and the remainder had a variety of benign lesions. There were no cases of ovarian carcinoma in this group. Eighty-six patients with unilocular cystic ovarian tumors were followed at 3- to 6-month intervals without surgery, and none have developed ovarian cancer. Complex cystic ovarian tumors were detected in 250 patients (3.2%). All tumors were10 cm in diameter and 89% were5 cm in diameter. One hundred thirty-five (55%) resolved spontaneously within 60 days, and 115 (45%) persisted. One hundred fourteen of these patients underwent operative tumor removal. Seven patients had ovarian carcinoma, 1 had primary peritoneal cancer, and 1 had metastatic breast cancer to the ovary.Unilocular ovarian cysts10 cm in diameter in asymptomatic postmenopausal women or womenor =50 years of age are associated with minimal risk for ovarian cancer. In contrast, complex ovarian cysts with wall abnormalities or solid areas are associated with a significant risk for malignancy. These data are important in determining optimal strategies for operative intervention in these patients.

Cryopreservation of mature oocytes can result in damage to the metaphase spindle due to the temperature sensitivity of microfilaments and microtubules. Cryopreservation of immature oocytes may circumvent this problem because these structures have not formed yet and the genetic material is enclosed within a nuclear envelope. Because intact oocyte cumulus-oocyte complexes (COC) are essential for normal maturation, we chose to cryopreserve immature intact COC. The aim of this study was to determine if immature COC cryopreserved by slow rate freezing or vitrification would resume meiosis upon thawing. In 2 separate experiments, immature COC (n = 102 and 79) were collected from cross-bred cattle by transvaginal ultrasound-guided aspiration and divided into 2 groups. For both experiments, the first group (n = 64 and 40) was placed directly into maturation medium (TCM 199 supplemented with 10% fetal bovine serum, 0.2 mM sodium pyruvate, 2 mM glutamine, and 5 μg mL–1 of FSH) and cultured for 22 h under 5% CO2 in air atmosphere at 39°C. In experiment 1, COC (n = 38) in the second group were cryopreserved by a slow rate freezing protocol. The COC were equilibrated for 5 min in 1.5 M ethylene glycol (EG), and 5 COC were loaded into 0.25-mL straws and placed into the cooling chamber of a Freeze Control unit at –6°C. After 5 min, straws were seeded, then cooled at 0.5°C per min to –35°C before plunging into LN. After storage in LN for 5 days, straws were removed from LN, thawed by placing straws in a 35°C water bath, and COC put into maturation as described above. In experiment 2, COC (n = 39) in the second group were cryopreserved by vitrification using a 3-step procedure. The COC were equilibrated in solutions consisting of 10% glycerol then 10% glycerol and 20% EG in PBS for 5 min each. The COC were then placed in a solution of 24% glycerol and 26% EG, and 1 to 3 COC were placed onto a cryotop device in minimal medium and plunged into LN within 45 s. After storage in LN for 2 days, COC were thawed by placing the cryotop device directly into a warmed dilution solution consisting of 0.5 M galactose in PBS. After 5 min in the dilution solution, COC were put into maturation as described above. For all groups, after 22 h of maturation cumulus cells were stripped from the oocytes by vortexing and oocytes were placed on slides for fixation in methanol acetic acid and stained with 1% orcein to determine the nuclear stage. In experiment 1, oocytes cryopreserved by slow rate freezing matured to MII at the same rate as control oocytes (45 v. 55%, P = 0.44). In experiment 2, oocytes cryopreserved by vitrification matured to MII at a lower rate than controls (49 v. 79%, P = 0.01). These results show that cryopreservation of immature intact COC is a viable alternative to cryopreservation of mature oocytes. Further studies are needed to optimize either slow rate freezing or vitrification of intact COC and determine the developmental competence of cryopreserved oocytes following fertilization.

The efficiency of in vitro production (IVP) has remained low due to an inadequate in vitro maturation (IVM) system. Thus far, the most promising methods of improving IVM utilise cAMP modulators to slow the maturation process by keeping cAMP high. This experiment compares standard IVM to an extended IVM as previously described by Albuz (2010 Hum. Reprod. 25, 2999–3011). The extended IVM consists of a 2-h pre-IVM phase with FSK (an adenylate cyclase activator) and 3-isobutyl-1-methylxanthine [IBMX, a nonspecific phosphodiesterase (PDE) inhibitor], followed by a 31-h IVM phase with cilostamide (a PDE3 inhibitor). 3-Isobutyl-1-methylxanthine inhibits all PDE in both the oocyte and CC, whereas cilostamide inhibits PDE3 only in the oocyte, allowing a gradual reversal of inhibition. Bovine oocytes (n = 363) were obtained by transvaginal ultrasound-guided aspiration of both Brahman and Angus cattle over 4 collection days. Oocytes from each cow were divided into 2 groups. The first group was placed in standard 23-h IVM medium composed of TCM-199 supplemented with 10% fetal bovine serum, sodium pyruvate, penicillin and streptomycin, glutamine, and FSH, and cultured in 5% CO2 at 39°C. A subset of oocytes was removed from maturation at 8, 13, 18, and 23 h. The second group was placed into a pre-IVM medium of HEPES-TALP supplemented with 100 μM FSK and 500 μM IBMX for 2 h at 39°C, and then moved into standard maturation medium supplemented with 20 μM cilostamide for 31 h (5% CO2, 39°C). Oocytes were sampled at 8, 13, 18, 23, 28, and 33 h. Oocytes were stained with 1% orcein and nuclear status was examined for each sample time (Table 1). Data were analysed using a chi-squared test. At 8 h, there was a significant difference (P

Ninety-four patients with squamous cell carcinoma invading the cervical stroma to a depth of >3.0-5.0 mm with 7 mm or less in horizontal spread (FIGO Stage IA2) were evaluated. Depth and lateral extent of stromal invasion were verified using an ocular micrometer. Cell type and lymph vascular space invasion (LVSI) were recorded in each case. Patients were treated primarily by radical hysterectomy with pelvic lymphadenectomy, and those with lymph node metastases were offered postoperative radiation. Following treatment, patients were seen at 3-month intervals for 2 years, and every 6 months thereafter. The mean duration of follow-up was 6.9 years (range 0.4-23.5 years). Seven of 94 patients (7.4%) had lymph node metastases. Five patients had 1 positive node, 1 patient had 2 positive nodes, and 1 patient had 3 positive nodes. Five patients developed recurrent cancer and 4 died of disease. LVSI was present in 31 cases (33%). Tumor recurrence was significantly increased in patients with positive LVSI (9.7% vs 3.2%). The 5-year survival rate of patients with LVSI was 89% vs 98% in patients without this finding (P = 0.058). The 5-year survival rate of all Stage IA2 cervical cancer patients was 95%. Patients with Stage IA2 cervical cancer have a significant risk of lymph node metastases and should be treated by radical hysterectomy with pelvic lymphadenectomy. LVSI is an important prognostic variable in these patients and should be recorded in all cases.

A 19-year-old Hispanic nullipara experienced the rapid growth of an oral lesion on the right lower gingiva which she had first noticed at 29 weeks gestation. The lesion interfered with oral hygiene and eating. At surgery, the lesion measured 3.5 x 2.5 x 2.0 cm. Biopsy confirmed a pyogenic granuloma ("granuloma gravidarum"). Panorex films showed no bony invasion. The lesion was excised using the Nd:YAG laser under general anesthesia when the patient had reached 36 3/7 weeks gestation. We chose the Nd:YAG laser over the CO2 laser for the removal of this very vascular lesion, because of its superior coagulation characteristics. This technique results in removal of the lesion with less danger of bleeding than with any other surgical technique. The patient did well postoperatively, delivered a healthy 3,884 g infant at 40 6/7 weeks gestation, and has had no recurrence after 15 months of follow-up.

Hybrid exchange density functional theory is used to study the wide band gap chalcopyrite CuAlS2. The formation energies of charged and neutral intrinsic defects are calculated for different environmental conditions, and it is shown that CuAlS2 is a p-type material that cannot be type inverted through the formation of intrinsic defects. The calculated band gap states associated with the different intrinsic defects are used to comment on the origin of the observed CuAlS2 photoluminescence emissions. The origin and stability of ordered defect compounds derived from CuAlS2 are investigated, and it is concluded that CuAl5S8 is a stable ordered defect compound, albeit in a small region of phase space.

The methodology for the calculation of charged defects using the CRYSTAL program is discussed. Two example calculations are used to illustrate the methodology: He+ ions in a vacuum and two intrinsic charged defects, Cu vacancies and Ga substitution for Cu, in the chalcopyrite CuGaS2.

High surface area (HS) A1F3 samples have been examined by X-ray photoelectron spectroscopy (XPS). The experimentally observed binding energy (BE) shifts were analysed by reference to core level BEs obtained from ab initio total energy calculations on a range of different, clean and hydroxylated alpha- and beta-A1F3 surfaces. Examination of the two components visible in the A1 2p emission indicates that surface A13+ sites can, depending on the local geometric structure, contribute to both a high BE peak at 77.0 eV and a low BE peak at 76.1 eV. Consequently, the areas under the peaks do not quantitatively correlate with surface area or Lewis acidity. However, a significant correlation between the number of surface A1 centres with dangling F or OH groups and the appearance of an A1 2p emission component at a BE lower than in the alpha-A1F3 bulk is predicted. The experimental F 1s emission data indicate that dangling F species are essentially absent. Examination of the O 1s emission suggests that HS A1F3 handled at room temperature under any practical laboratory conditions, including glovebox environments, probably contains intrinsically a significant amount of OH groups and adsorbed water, which results in the covering of A1F3 surfaces by dangling or bridging OH groups. These Bronsted acid species must be removed by treatment at higher temperature before HS A1F3 reagents can fully develop their Lewis acidity.

To assess a possible role of ticks as the maintenance host for epizootic strains of Venezuelan equine encephalomyelitis (VEE) virus, laboratory experiments were conducted to determine if ticks could become infected, maintain, and transmit the virus. Larval and nymphal Amblyomma cajennense (F.) and larval Dermacentor nitens Neumann ticks were exposed to epizootic VEE virus (Trinidad donkey strain) by allowing them to feed on viremic guinea pigs (strain 13). In A. cajennense, transstadial transmission was observed from larvae to nymphs and adults. Horizontal viral transmission to a mammalian host was accomplished by nymphs. Infection rates in nymphs and adults were 2% (42/2,750) and 4% (9/244), respectively, after ingestion of virus as larvae. Virus was detected in A. cajennense adult ticks for up to 171 d after infection in the larval stage. A. cajennense, exposed as nymphs, ingested virus but did not become infected (0/164 after 10 d after taking an infective bloodmeal). No virus was detected in D. nitens 7 d after exposure. These findings suggest that A. cajennense potentially could be involved in an interepizootic maintenance cycle of epizootic VEE viral strains.

The current study employs hybrid-exchange density functional theory to show that the Lewis base, NH(3), binds to the beta-AlF(3) (100) surface with a binding energy (BE) of up to -1.96 eV per molecule. This is characteristic of a strong Lewis acid. The binding of NH(3) to the surface is predominately due to electrostatic interactions. There is only a small charge transfer from the NH(3) molecule to the surface. The BE as a function of coverage is computed and used to develop a lattice Monte Carlo model which is used to predict the temperature programed desorption (TPD) spectrum. Comparison with experimental TPD studies of NH(3) from beta-AlF(3) strongly suggests that these structural models and binding mechanisms are good approximations to those that occur on real AlF(3) surfaces.

The recently discovered high surface area AlF3 catalyst is characterised with respect to surface composition and structure using calculations based on density functional theory. Under typical reaction conditions the surfaces are found to expose five fold coordinated Al reaction centres and to preferentially adsorb water. The acidic centres are probed using NH3 adsorption which binds strongly indicating strong Lewis acidity. The predicted temperature probed desorption spectrum has features from competing surfaces and features due to strong intermolecular interactions, which are used to interpret the observed spectrum.

The current study employs state of the art hybrid-exchange density functional theory (DFT) to investigate the Lewis acidic sites on the β-AlF3 (100) surface. It is shown that the strong Lewis base, NH3, binds to the surface with a binding energy of up to 1.9 eV. This demonstrates that the material is strongly Lewis acidic. We also consider the binding of the weak Lewis base CO to the surface. We calculate the shift in its stretch frequency compared to the gas phase molecule. Shifts are compared to experimental data and are shown to be typical of strong Lewis acidity.

Solid aluminium fluorides have great potential for use in a range of reactions that are catalysed by strong Lewis acids. However, very little is known about the detailed atomic scale structure of their surfaces. We present new results for the surface structure of β-AlF3 based on first principles simulation and compare these with our earlier work on α-AlF3. On the basis of these simulations we can explain the observed reactivity of the aluminium fluoride materials. We can also use these results to postulate a mechanism for the observed high reactivity shown by amorphous, ‘high-surface area’ AlF3.

Strong Lewis acid catalysts are widely used in a variety of industrial processes including Cl/F exchange reactions. Aluminium fluorides (AlF3) have great potential for use in such reactions. Despite the importance of the surface in the catalytic process little is known about the detailed atomic scale structure of AlF3 surfaces. In the current study we employ state of the art total energy calculations based on hybrid-exchange density functional theory to predict the composition and structure of the (100) surface of beta-AlF3 for the first time. We examine six possible terminations of the beta-AlF3 (100) surface and demonstrate that there are two relatively low energy terminations that result in the formation of under co-ordinated Al3+ ions at the surface. Such under co-ordinated ions are expected to be strong Lewis acid sites. This is the first ab initio determination of the atomic scale structure of such sites on the surface of beta-AlF3.