Tuning the conditions for the deposition of nanocrystalline diamond by hot filament chemical vapour deposition

Although large focus has been placed into the deposition of nanocrystalline and ultra-nanocrystalline diamond films, most of this research uses microwave plasma assisted CVD systems. However, the growth conditions used in microwave systems cannot be directly used in hot-filament CVD systems. This paper, aims to enlarge the knowledge of the diamond film depositing process. H2/CH4/Ar gas mixtures have been used to deposit micro, nano and ultra-nanocrystalline diamond films by hot-filament CVD systems. Additionally, the distance between the filaments array and the substrate was varied, in order to observe its effect and consequently the effect of a lower substrate temperature in the nucleation density and deposition. All the samples were characterized for microstructure and quality, using scanning electron microscopy and Raman spectroscopy.     

Polarization ellipse and Stokes parameters in geometric algebra

In this paper, we use geometric algebra to describe the polarization ellipse and Stokes parameters. We show that a solution to Maxwell's equation is a product of a complex basis vector in Jackson and a linear combination of plane wave functions. We convert both the amplitudes and the wave function arguments from complex scalars to complex vectors. This conversion allows us to separate the electric field vector and the imaginary magnetic field vector, because exponentials of imaginary scalars convert vectors to imaginary vectors and vice versa, while exponentials of imaginary vectors only rotate the vector or imaginary vector they are multiplied to. We convert this expression for polarized light into two other representations: the Cartesian representation and the rotated ellipse representation. We compute the conversion relations among the representation parameters and their corresponding Stokes parameters. And finally, we propose a set of geometric relations between the electric and magnetic fields that satisfy an equation similar to the Poincaré sphere equation.     

Facetted patchy particles through entropy-driven patterning of mixed ligand SAMS

We present a microscopic theory that describes the ordering of two distinct ligands on the surface of a facetted nanoparticle. The theory predicts that when one type of ligand is significantly bulkier than all others, the larger ligands preferentially align themselves along the edges and vertices of the nanoparticle. Monte Carlo simulations confirm these predictions. We show that the intrinsic conformational entropy of the ligands stabilizes this novel edge-aligned phase.     

Low progesterone concentration during the development of the first follicular wave reduces pregnancy per insemination of lactating dairy cows

Objectives were to determine the effect of progesterone (P4) concentration on fertility of lactating dairy cows induced to ovulate follicles of the first follicular wave. Lactating dairy cows (n=989) at 38±3d postpartum were balanced by parity and body condition score and randomly assigned to 3 treatments: first follicular wave (FFW), first follicular wave with exogenous P4 (FFWP), or second follicular wave (SFW). All cows had their estrous cycle presynchronized with 2 injections of prostaglandin (PG) F(2α) given 14 d apart. Cows in the FFW and FFWP treatments started the ovulation synchronization protocol 3 d after the last PGF(2α) of the presynchronization protocol, whereas SFW cows received a GnRH injection (100 μg of gonadorelin diacetate; Cystorelin, Merial Ltd., Duluth, GA) 3 d after the last PGF(2α) of the presynchronization protocol and started the synchronization protocol 7 d later. The synchronization protocol consisted of GnRH on d -10, PGF(2α) on d -3, and GnRH concurrent with timed artificial insemination (AI) on d 0. Cows in the FFWP treatment received 2 controlled internal drug release inserts containing 1.38 g of P4 from d -8 to -3. Progesterone concentration was determined on d -10, -8, -6, -3, and 0 from all cows and at 7, 14, and 21 d after AI from a subsample of cows (n=170). Cows (n=715) had their ovaries scanned by ultrasound on d -10, -3, and 7 d. Pregnancy was diagnosed at 38 and 66 d after AI. Concentration of P4 from study d -8 to -3 was lowest for FFW cows (1.4±0.1 ng/mL) and similar between SFW (3.7±0.2 ng/mL) and FFWP (3.7±0.1 ng/mL) cows. Diameter of the dominant follicle on study d -3 was greater for FFW cows (16.5±0.3 mm) than for SFW cows (15.4±0.3 mm), but diameter of the dominant follicle of FFWP cows was not different (15.9±0.3 mm) compared with that of SFW and FFW cows. The incidence of multiple ovulation was largest for FFW cows (SFW=19.5, FFW=33.6, FFWP=19.0%), but pregnancy per AI (P/AI) at 66 d was smallest for FFW cows (SFW=38.9, FFW=22.3, FFWP=32.0%). Anovular cows in the SFW (19.4 vs. 42.8%) and FFWP (22.1 vs. 37.2%) treatments had reduced P/AI compared with cyclic cows, despite having similar or greater P4 concentration from study d -8 to -3, respectively. Estrus and ovulation synchronization protocols for lactating dairy cows must result in growth of ovulatory follicle under P4 concentration >2 ng/mL to ensure high P/AI.     

A Low-Protein,High-Carbohydrate Diet Increases Fatty Acid Uptake and Reduces Norepinephrine-Induced Lipolysis in Rat Retroperitoneal White Adipose Tissue

A low-protein, high-carbohydrate (LPHC) diet for 15 days increased the lipid content in the carcass and adipose tissues of rats. The aim of this work was to investigate the mechanisms of this lipid increase in the retroperitoneal white adipose tissue (RWAT) of these animals. The LPHC diet induced an approximately two- and tenfold increase in serum corticosterone and TNF-α, respectively. The rate of de novo fatty acid (FA) synthesis in vivo was reduced (50%) in LPHC rats, and the lipoprotein lipase activity increased (100%). In addition, glycerokinase activity increased (60%), and the phosphoenolpyruvate carboxykinase content decreased (27%). Basal [U-¹⁴C]-glucose incorporation into glycerol-triacylglycerol did not differ between the groups; however, in the presence of insulin, [U-¹⁴C]-glucose incorporation increased by 124% in adipocytes from only control rats. The reductions in IRS1 and AKT content as well as AKT phosphorylation in the RWAT from LPHC rats and the absence of an insulin response suggest that these adipocytes have reduced insulin sensitivity. The increase in NE turnover by 45% and the lack of a lipolytic response to NE in adipocytes from LPHC rats imply catecholamine resistance. The data reveal that the increase in fat storage in the RWAT of LPHC rats results from an increase in FA uptake from circulating lipoproteins and glycerol phosphorylation, which is accompanied by an impaired lipolysis that is activated by NE.     

Producing a sulfamethazine quality control material under the framework of ISO/CD Guide 80

The increasing use of antimicrobial agents such as sulfonamides by the pig industry is of concern, since residues in both pork and its by-products, when derived from animals treated improperly, can endanger human health. The aim of this study was to establish the production conditions and to evaluate the homogeneity and the stability of sulfamethazine in porcine liver quality control material, produced 'in-house' for use in ring tests of the laboratory network of residues and contaminants of the Ministry of Agriculture, Livestock and Food Supply, Brazil. In the process of preparing the material, a FOSS blender was used, where the samples were ground to obtain a homogeneous mass, which was packed in polypropylene bottles. The material resulting from this process of homogenisation was sampled and analysed by LC/MS/MS. The analytical results were statistically evaluated by one-way ANOVA. According to statistical evaluation, the material produced was considered homogeneous, with 95% confidence. Stability tests were performed with the bottles stored under the specified storage conditions. They were randomly selected and analysed in duplicate by the same analytical method as the homogeneity study. The analytical results were statistically evaluated by the procedures for a stability check described in ISO 13528:2005, indicating that the material was unstable under the conditions of storage.     

FGF10 inhibits dominant follicle growth and estradiol secretion in vivo in cattle

Fibroblast growth factors (FGFs) are involved in paracrine control of follicle development. It was previously demonstrated that FGF10 decreases estradiol (E(2)) secretion in granulosa cell culture and that theca cell FGF10 mRNA expression is decreased in healthy follicles from abattoir ovaries. The main objectives of this study were to evaluate FGF10 and FGFR2b mRNA expression during follicular development in vivo, to evaluate the effect of FGF10 on follicle growth using Bos taurus taurus cows as a model, and to gain more insight into the mechanisms through which FGF10 inhibits steroidogenesis. Messenger RNA encoding both FGF10 and FGFR2b (main FGF10 receptor) was significantly more expressed in subordinate follicles (SFs) than in dominant follicles (DFs). The intrafollicular injection of FGF10 into the largest growing follicle at 7-8?mm in diameter interrupted the DF growth in a dose-dependent manner (11±0.4, 8.3±1 and 5.9±0.3?mm for 0, 0.1, and 1?μg/ml FGF10, respectively, at 72?h after treatment; P<0.05). In a third experiment, follicles were obtained 24?h after FGF10 (1?μg/ml) or PBS treatment through ovariectomy. In theca cells, FGF10 treatment did not affect mRNA encoding steroidogenic enzymes, LHCGR and IGFBPs, but significantly upregulated FGF10 mRNA expression. The expression of CYP19A1 mRNA in granulosa cells was downregulated by FGF10 treatment, which was accompanied by a 50-fold decrease in E(2) production, and decreased cyclin D2 mRNA. These results have shown that FGF10 and its receptor FGFR2b are more expressed in SFs and provide solid in vivo evidence that FGF10 acts as an important regulator of follicular growth in cattle.     

Evaluation of methods of resynchronization for insemination in cows of unknown pregnancy status

The objectives of this study were to evaluate the effect of 3 methods of resynchronization of estrus and ovulation for lactating dairy cows of unknown pregnancy status on conception rate and time to pregnancy. Holstein cows (n = 495) were randomly assigned to 1 of 3 treatments: 1) control (n = 167), resynchronization with a timed AI protocol upon diagnosis of nonpregnancy on d 31 after preenrollment AI (PAI); 2) CIDR-G (n = 159), use of an intravaginal progesterone insert from d 14 to 21 after AI, with AI at estrus from d 21 to 24 and initiation of a timed AI protocol on d 24 after AI in cows not reinseminated; 3) CIDR-G + ECP (n = 169), the same treatment as CIDR-G but with an injection of 1 mg of estradiol cypionate at the time of progesterone insert removal. Cows were continuously reenrolled in the same treatment until diagnosed as pregnant, which resulted in a total of 1,148 AI (495 PAI and 653 resynchronized AI; RAI). Blood was collected from 1,001 cows on d 14, 21, and 24 after each AI for analysis of progesterone, and ovaries were scanned on d 21, 24, and 31 after AI. The presence of an active corpus luteum was presumed based on progesterone ≥1 ng/mL. Pregnancy was diagnosed by ultrasonography on d 31 and 61 after AI. The presence of an active corpus luteum and the incidence of luteolysis were similar for all treatments from d 14 to 24; however, luteolysis increased in the CIDR-G + ECP treatment from d 21 to 24. Conception rates for the PAI and all AI were similar on d 31 and 61 after insemination. Conception rates at 31 and 61 d after the RAI were also similar among treatments. Overall pregnancy loss for the PAI, RAI, and all AI were similar for all treatments. The accuracy of estrous detection, based on progesterone concentration within 2 d of detection of estrus, was similar for all treatments for the RAI and averaged 95.3%. The estrus-detection rate (EDR) decreased for the CIDR-G and CIDR-G + ECP treatments from d 14 to 21, but increased from d 21 to 24 compared with control cows; however, the EDR was smaller for cows in the CIDR-G treatment during the entire resynchronization period compared with those in the CIDR-G + ECP and control groups. The reinsemination interval was reduced in cows receiving the CIDR-G + ECP treatment compared with control cows because of increased EDR after removal of the intravaginal insert; however, the interval from study enrollment to pregnancy was not different among treatments. These results indicate that the reproductive performance of dairy cows did not differ among the 3 resynchronization treatments evaluated.     

Reduced progesterone concentration during growth of the first follicular wave affects embryo quality but has no effect on embryo survival post transfer in lactating dairy cows

Fertility of lactating dairy cows is associated with reduced progesterone (P(4)) concentration compared with nonlactating animals. The objective of the current study was to determine whether P(4) during growth of the first follicular wave (FFW) affects embryo quality. Lactating Holstein cows at 33±3 days post partum were allocated to one of three treatments. Cows in the FFW and FFW with P(4) (FFWP) treatments started the superstimulation protocol on day 1 of the estrous cycle and second follicular wave (SFW) cows started the superstimulation protocol on estrous cycle day 7. Cows were superstimulated with 400 mg of NIH-FSH-P1 (FSH) given twice daily for 5 days, two prostaglandin F(2α) (PGF(2α)) injections given with the ninth and tenth injections of FSH, GNRH given 48 h after the first PGF(2α) injection, and timed insemination 12 and 24 h after the GNRH injection. Cows in the FFWP treatment received two intravaginal P(4) inserts during the superstimulation. Embryos were recovered 6.5 days after artificial insemination and excellent/good and fair embryos were frozen and transferred. Blood was sampled daily from estrous cycle day 0 until insemination from donor cows. During the superstimulation protocol, P(4) was (P<0.01) greatest for SFW cows followed by FFWP and FFW cows respectively. The percentage of embryos-oocytes from SFW and FFWP cows classified as excellent/good and fair embryos was (P=0.02) greater than those of FFW cows. Pregnancy per embryo transfer was not (P≥0.73) affected by embryo donor treatment. Reduced embryo quality of cows induced to ovulate the follicles from the first follicular wave is a consequence of reduced P(4) during follicle growth.