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1.
Phys Rev Lett ; 132(3): 035101, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38307081

RESUMO

Magnetic reconnection is a ubiquitous and fundamental process in plasmas by which magnetic fields change their topology and release magnetic energy. Despite decades of research, the physics governing the reconnection process in many parameter regimes remains controversial. Contemporary reconnection theories predict that long, narrow current sheets are susceptible to the tearing instability and split into isolated magnetic islands (or plasmoids), resulting in an enhanced reconnection rate. While several experimental observations of plasmoids in the regime of low-to-intermediate ß (where ß is the ratio of plasma thermal pressure to magnetic pressure) have been made, there is a relative lack of experimental evidence for plasmoids in the high-ß reconnection environments which are typical in many space and astrophysical contexts. Here, we report strong experimental evidence for plasmoid formation in laser-driven high-ß reconnection experiments.

2.
Rev Sci Instrum ; 95(6)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38912911

RESUMO

Penumbral imaging is a technique used in plasma diagnostics in which a radiation source shines through one or more large apertures onto a detector. To interpret a penumbral image, one must reconstruct it to recover the original source. The inferred source always has some error due to noise in the image and uncertainty in the instrument geometry. Interpreting the inferred source thus requires quantification of that inference's uncertainty. Markov chain Monte Carlo algorithms have been used to quantify uncertainty for similar problems but have never been used for the inference of the shape of an image. Because of this, there are no commonly accepted ways of visualizing uncertainty in two-dimensional data. This paper demonstrates the application of the Hamiltonian Monte Carlo algorithm to the reconstruction of penumbral images of fusion implosions and presents ways to visualize the uncertainty in the reconstructed source. This methodology enables more rigorous analysis of penumbral images than has been done in the past.

3.
Sci Rep ; 14(1): 9218, 2024 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649444

RESUMO

For reducing Campylobacter (C.) in the food production chain and thus the risk to the consumer, the combined application of different measures as a multiple-hurdle approach is currently under discussion. This is the first study to investigate possible synergistic activities in vivo, aiming at reducing intestinal C. jejuni counts by administering (i) bacteriophages (phages) in combination with a competitive exclusion (CE) product and (ii) carvacrol combined with organic acids. The combined application of the two selected phages (Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1) and the CE product significantly reduced C. jejuni loads by 1.0 log10 in cecal and colonic contents as well as in cloacal swabs at the end of the trial (33 and 34 days post hatch). The proportion of bacterial isolates showing reduced phage susceptibility ranged from 10.9% (isolates from cecal content) to 47.8% (isolates from cloacal swabs 32 days post hatch) for the Fletchervirus phage, while all tested isolates remained susceptible to the Firehammervirus phage. The use of carvacrol combined with an organic acid blend (sorbic acid, benzoic acid, propionic acid, and acetic acid) significantly reduced Campylobacter counts by 1.0 log10 in cloacal swabs on day 30 only.


Assuntos
Bacteriófagos , Galinhas , Cimenos , Cimenos/farmacologia , Animais , Bacteriófagos/fisiologia , Galinhas/microbiologia , Infecções por Campylobacter/prevenção & controle , Infecções por Campylobacter/microbiologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Campylobacter jejuni/virologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter/efeitos dos fármacos , Campylobacter/virologia
4.
Rev Sci Instrum ; 95(10)2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39356193

RESUMO

The Particle Time of Flight (PTOF) detector is a chemical vapor deposition diamond-based detector used to measure bang times in low-yield (≲ 1015 neutrons) experiments at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL). Historically, the impulse response for PTOF diamond detectors has been obtained from x-ray timing shots on the NIF and shots on the MegaRay pulsed electron accelerator at LLNL. The impulse response may alternatively be obtained using single particle interactions with the detector, at substantially less cost and higher frequency compared to NIF timing shots, which typically occur months apart. Here, the response of a PTOF detector setup is characterized by statistically averaging a large number of single particle waveforms. A high fidelity instrument response function can be constructed in this way. This is confirmed by comparison of the single particle counting-constructed response to the impulse response function measured for the same detector at LLNL's MegaRay facility.

5.
Rev Sci Instrum ; 95(9)2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39315911

RESUMO

Image plates (IPs), or phosphor storage screens, are a technology employed frequently in inertial confinement fusion (ICF) and high energy density plasma (HEDP) diagnostics because of their sensitivity to many types of radiation, including, x rays, protons, alphas, beta particles, and neutrons. Prior studies characterizing IPs are predicated on the signal level remaining below the scanner saturation threshold. Since the scanning process removes some signal from the IP via photostimulated luminescence, repeatedly scanning an IP can bring the signal level below the scanner saturation threshold. This process, in turn, raises concerns about the signal response of IPs after an arbitrary number of scans and whether such a process yields, for example, a constant ratio of signal between the nth and n + 1st scan. Here, the sensitivity of IPs is investigated when scanned multiple times. It is demonstrated that the ratio of signal decay is not a constant with the number of scans and that the signal decay depends on the x-ray energy. As such, repeatedly scanning an IP with a mixture of signal types (e.g., x ray, neutron, and protons) enables ICF and HEDP diagnostics employing IPs to better isolate a particular signal type.

6.
Rev Sci Instrum ; 95(9)2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39315912

RESUMO

Image plates (IPs) are a quickly recoverable and reusable radiation detector often used to measure proton and x-ray fluence in laser-driven experiments. Recently, IPs have been used in a proton radiography detector stack on the OMEGA laser, a diagnostic historically implemented with CR-39, or radiochromic film. The IPs used in this and other diagnostics detect charged particles, neutrons, and x-rays indiscriminately. IPs detect radiation using a photo-stimulated luminescence (PSL) material, often phosphor, in which electrons are excited to metastable states by ionizing radiation. Protons at MeV energies deposit energy deeper into the IP compared with x rays below ∼20 keV due to the Bragg peak present for protons. This property is exploited to discriminate between radiation types. Doses of mono-energetic protons between 1.7 and 14 MeV are applied to IPs using the MIT linear electrostatic ion accelerator. This paper presents the results from consecutive scans of IPs irradiated with different proton energies. The PSL ratios between subsequent scans are shown to depend on proton energy, with higher energy protons having lower PSL ratios for each scan. This finding is separate from the known energy dependence in the absolute sensitivity of IPs. The results can be compared to complimentary work on x rays, showing a difference between protons and x rays, forging a path to discriminate between proton and x-ray fluence in mixed radiation environments.

7.
Rev Sci Instrum ; 95(10)2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39356191

RESUMO

This paper reports on investigations on the impact of higher neutron fluences on the detection efficiency of protons with CR-39, a charged particle track detector. CR-39 is widely used as a diagnostic for inertial fusion applications and is an integral component of numerous particle diagnostics at the OMEGA laser facility and National Ignition Facility. As experiments continue to produce higher and higher yields, existing diagnostics are impacted by higher particle fluences than they were originally designed for. This paper presents data from experiments measuring proton signal on pieces of CR-39 with different levels of neutron fluence with two different etch times. The experiments show a decrease in signal recovery with increased neutron fluence, which is exacerbated at longer etch times. At 3 h etch time, data suggest a 17% ± 7% signal loss at 1.3 × 105 neutron-induced tracks per cm2 and a 67% ± 21% loss at 6 h etch time. Careful signal isolation techniques can recover most of the proton tracks even with moderate neutron fluence.

8.
Rev Sci Instrum ; 95(9)2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39302171

RESUMO

Radiochromic film (RCF) and image plates (IPs) are both commonly used detectors in diagnostics fielded at inertial confinement fusion (ICF) and high-energy-density physics (HEDP) research facilities. Due to the intense x-ray background in all ICF/HEDP experiments, accurately calibrating the optical density of RCF as a function of x-ray dose, and the photostimulated luminescence per photon of IPs as a function of x-ray energy, is necessary for interpreting experimental results. Various measurements of the sensitivity curve of different IPs to x rays have been performed [Izumi et al., Proc. SPIE 8850, 885006 (2013) and Rosenberg et al., Rev. Sci. Instrum. 90(1), 013506 (2019)]; however, calibrating RCF is a tedious process that depends on factors such as the orientation in which the RCF is scanned in the film scanner and the batch of RCF used. These issues can be mitigated by cross-calibrating RCF with IPs to enable the use of IPs for the determination of dose on the RCF without scanning the RCF. Here, the first cross-calibration of RCF with IPs to quasi-monoenergetic titanium, copper, and molybdenum K-line x rays is presented. It is found that the IP-inferred dose rates on the RCF for the Ti and Mo x rays agree well with the measured dose rates, while the IP-inferred dose rate for the Cu x rays is larger than the measured dose rate by ∼2×. Explanations for this discrepancy and plans for future work are discussed.

9.
Rev Sci Instrum ; 95(10)2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39365111

RESUMO

To benchmark the accuracy of the models and improve the predictive capability of future experiments, the National Ignition Facility requires measurements of the physical conditions inside inertial confinement fusion hohlraums. The ion temperature and bulk motion velocity of the gas-filled regions of the hohlraum can be obtained by replacing the helium tamping gas in the hohlraum with deuterium-tritium (DT) gas and measuring the Doppler broadening and Doppler shift of the neutron spectrum produced by nuclear reactions in the hohlraum. To understand the spatial distribution of the neutron production inside the hohlraum, we have developed a new penumbral neutron imager with a 12 mm diameter field of view using a simple tungsten alloy spindle. We performed the first experiment using this imager on a DT gas-filled hohlraum and successfully obtained the spatial distribution of neutron production in the hohlraum plasma. We will report on the design of the spindle, characterization of the detectors, and methodology of the image reconstruction.

10.
Rev Sci Instrum ; 95(9)2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39315908

RESUMO

Inertial Confinement Fusion and Magnetic Confinement Fusion (ICF and MCF) follow different paths toward goals that are largely common. In this paper, the claim is made that progress can be accelerated by learning from each other across the two fields. Examples of successful cross-community knowledge transfer are presented that highlight the gains from working together, specifically in the areas of high-resolution x-ray imaging spectroscopy and neutron spectrometry. Opportunities for near- and mid-term collaboration are identified, including in chemical vapor deposition diamond detector technology, using gamma rays to monitor fusion gain, handling neutron-induced backgrounds, developing radiation hard technology, and collecting fundamental supporting data needed for diagnostic analysis. Fusion research is rapidly moving into the igniting and burning regimes, posing new opportunities and challenges for ICF and MCF diagnostics. This includes new physics to probe, such as alpha heating; increasingly harsher environmental conditions; and (in the slightly longer term) the need for new plant monitoring diagnostics. Substantial overlap is expected in all of these emerging areas, where joint development across the two subfields as well as between public and private researchers can be expected to speed up advancement for all.

11.
Rev Sci Instrum ; 94(3): 033510, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37012781

RESUMO

The Particle Time of Flight (PTOF) diagnostic is a chemical vapor deposition diamond detector used for measuring multiple nuclear bang times at the National Ignition Facility. Due to the non-trivial, polycrystalline structure of these detectors, individual characterization and measurement are required to interrogate the sensitivity and behavior of charge carriers. In this paper, a process is developed for determining the x-ray sensitivity of PTOF detectors and relating it to the intrinsic properties of the detector. We demonstrate that the diamond sample measured has a significant non-homogeneity in its properties, with the charge collection well described by a linear model ax + b, where a = 0.63 ± 0.16 V-1 mm-1 and b = 0.00 ± 0.04 V-1. We also use this method to confirm an electron to hole mobility ratio of 1.5 ± 1.0 and an effective bandgap of 1.8 eV rather than the theoretical 5.5 eV, leading to a large sensitivity increase.

12.
Rev Sci Instrum ; 93(11): 113534, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36461490

RESUMO

Charged particle spectrometry is a critical diagnostic to study inertial-confinement-fusion plasmas and high energy density plasmas. The OMEGA Laser Facility has two fixed magnetic charged particle spectrometers (CPSs) to measure MeV-ions. In situ calibration of these spectrometers was carried out using 241Am and 226Ra alpha emitters. The alpha emission spectrum from the sources was measured independently using surface-barrier detectors (SBDs). The energy dispersion and broadening of the CPS systems were determined by comparing the CPS measured alpha spectrum to that of the SBD. The calibration method significantly constrains the energy dispersion, which was previously obtained through the measurement of charged particle fusion products. Overall, a small shift of 100 keV was observed between previous and the calibration done in this work.

13.
Rev Sci Instrum ; 92(6): 063502, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243553

RESUMO

We report on the design and implementation of a new system used to characterize the energy-dependent x-ray transmission curve, Θ(E), through filters used in high-energy density physics diagnostics. Using an Amptek X-123-CdTe x-ray spectrometer together with a partially depleted silicon surface barrier detector, both the energy spectrum and total emission of an x-ray source have been accurately measured. By coupling these detectors with a custom PROTO-XRD x-ray source with interchangeable cathodes, accurate characterizations of Θ(E) for filters of varying materials and thicknesses have been obtained. The validity of the technique has been confirmed by accurately reproducing areal densities for high-purity filters with known x-ray transmission properties. In this paper, the experimental setup is described and the results of absorption calibrations performed on a variety of different filters are presented.

14.
Rev Sci Instrum ; 92(8): 083506, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470381

RESUMO

New designs and a new analysis technique have been developed for an existing compact charged-particle spectrometer on the NIF and OMEGA. The new analysis technique extends the capabilities of this diagnostic to measure arbitrarily shaped ion spectra down to 1 MeV with yields as low as 106. Three different designs are provided optimized for the measurement of DD protons, T3He deuterons, and 3He3He protons. The designs are highly customizable, and a generalized framework is provided for optimizing the design for alternative applications. Additionally, the understanding of the detector's response and uncertainties is greatly expanded upon. A new calibration procedure is also developed to increase the precision of the measurements.

15.
Eur J Microbiol Immunol (Bp) ; 10(3): 131-138, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32750025

RESUMO

Carvacrol, a primary constituent of plant essential oils (EOs), and its antimicrobial activity have been the subject of many in vitro studies. Due to an increasing demand for alternative antimicrobials and an emerging number of antibiotic resistant bacteria, the use of essential oils has played a major role in many recent approaches to reduce Campylobacter colonization in poultry before slaughter age. For that purpose, the reducing effect of carvacrol on Campylobacter jejuni prevalence in broilers was determined in vivo in an experimental broiler chicken model during an entire fattening period. Carvacrol was added to the feed in a concentration of 120 mg/kg feed four days post hatch until the end of the trial. In this study, we demonstrated a statistically significant decrease of C. jejuni counts by 1.17 decadic logarithm (log10) most probable number (MPN)/g in cloacal swabs during starter and grower periods (corresponding to a broilers age between 1 and 28 days). Similar results were observed for colon enumeration at the end of the trial where C. jejuni counts were significantly reduced by 1.25 log10 MPN/g. However, carvacrol did not successfully reduce Campylobacter cecal colonization in 33-day-old broilers.

16.
Dtsch Tierarztl Wochenschr ; 103(8-9): 340-8, 1996.
Artigo em Alemão | MEDLINE | ID: mdl-9011504

RESUMO

The production of monozygotic twins/multiplets in livestock animal can be achieved either by microsurgical bisection of embryos at the morular- or blastocyst stage, isolation and proliferation of blastomeres from early cleavage stages or nuclear transfer. While the success rates of micro-surgical bisection are high in ruminants (pregnancy rates approximately 50%, twinning rates 20-40%) in polyovulatory species such as swine, the efficiency is low with an average of 20% embryonic survival and 2% monozygotic twins that can positively identified via DNA-fingerprinting. Isolated blastomeres from multicellular embryos still possess great developmental capacity in vitro to progress to the blastocyst stage. However, their development in vivo is markedly reduced. This article summarizes the results obtained by the authors during several years of investigation. The results show for the first time that identical twins can be obtained in pigs which have been demonstrated to be a useful tool in biomedical research.


Assuntos
Animais Domésticos/fisiologia , Gravidez Múltipla/fisiologia , Gêmeos Monozigóticos , Animais , Animais Domésticos/embriologia , Blastocisto , Blastômeros , Bovinos , Células Clonais , Feminino , Microcirurgia/veterinária , Gravidez , Suínos/embriologia , Suínos/fisiologia
17.
J Reprod Fertil Suppl ; 48: 75-94, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8145216

RESUMO

On the basis of established surgical procedures for embryo recovery and transfer, the early pig embryo can be subjected to various manipulations aimed at a long-term preservation of genetic material, the generation of identical multiplets, the early determination of sex or the alteration of the genetic make-up. Most of these procedures are still at an experimental stage and despite recent considerable progress are far from practical application. Normal piglets have been obtained after cryopreservation of pig blastocysts hatched in vitro, whereas all attempts to freeze embryos with intact zona pellucida have been unsuccessful. Pig embryos at the morula and blastocyst stage can be bisected microsurgically and the resulting demi-embryos possess a high developmental potential in vitro, whereas their development in vivo is impaired. Pregnancy rates are similar (80%) but litter size is reduced compared with intact embryos and twinning rate is approximately 2%. Pig blastomeres isolated from embryos up to the 16-cell stage can be grown in culture and result in normal blastocysts. Normal piglets have been born upon transfer of blastocysts derived from isolated eight-cell blastomeres, clearly underlining the totipotency of this developmental stage. Upon nuclear transfer the developmental capacity of reconstituted pig embryos is low and < 10% develop to morulae or blastocysts in vitro. Pig oocytes can be stimulated parthenogenetically and up to 10% grow to blastocysts in the in vitro culture. Sex determination can be achieved either by separation of X and Y chromosome bearing spermatozoa by flow cytometry or by analysing the expression of the HY antigen in pig embryos from the eight-cell to morula stage. Microinjection of foreign DNA has been successfully used to alter growth and development of transgenic pigs, and to produce foreign proteins in the mammary gland or in the bloodstream, indicating that pigs can be used as donors for valuable human pharmaceutical proteins. Another promising area of gene transfer is the increase of disease resistance in transgenic lines of pigs. Approximately 30% of pig spermatozoa bind considerable amounts of foreign DNA preferably at the post-acrosomal region, suggesting that transgenic animals can be obtained more efficiently than with the usual microinjection procedure. To increase gene transfer efficiency, considerable research efforts have been made to establish embryonic stem (ES) cells, but so far there is no definite proof of totipotency of the generated pig ES-like cells through viable chimaeras. In general, biotechnological procedures are much less advanced in pigs than in cows.


Assuntos
Embrião de Mamíferos/cirurgia , Microcirurgia/métodos , Suínos/embriologia , Animais , Transferência Embrionária/veterinária , Técnicas de Transferência de Genes/veterinária , Tamanho da Ninhada de Vivíparos , Partenogênese
18.
J Reprod Fertil ; 100(1): 163-72, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8182585

RESUMO

Porcine morulae and blastocysts were microsurgically bisected and the resulting zona pellucida-free demi-embryos were either cultured in vitro for 48 h or transferred after 24 h of culture into--24 h asynchronous recipients. All demi-embryos were evaluated according to morphological criteria and classified into three categories (excellent, fair or degenerated). The average diameter and the number of cells were determined. Of 1162 bisected embryos, 764 pairs (66%) were evaluated as transferable after 24 h of culture in vitro. The average diameter after 48 h of culture in vitro was different (P < 0.01) among demi-embryos of the three morphological categories as was the number of cells. The greatest diameter and the greatest number of cells were found in demi-embryos classified as morphologically excellent. A total of 22 of 27 recipients (81.5%) remained pregnant and 21 recipients delivered 126 piglets of which six were stillborn. The survival rate of demi-embryos in farrowing recipients was 21.2% (126 of 594). Litter size was significantly reduced in recipients after transfer of demi-embryos compared with that of mated controls (6.0 +/- 2.5 versus 10.8 +/- 2.1 piglets). Similarly, the postpartum losses of piglets were higher in the experimental than in the control gilts (26.7% versus 11.6%). Duration of gestation, average birth weight and daily weight gain were not affected. Among the 126 piglets, seven pairs of identical twins (2.3% of 311 transferred pairs) were identified using several genetic markers in blood (blood groups, polymorphic enzymes and plasma proteins) in a total of 25 gene loci. DNA fingerprinting revealed an identical banding pattern between the two partners of each of the seven pairs. Birth and weaning weight as well as daily weight gain varied considerably between monozygotic partners.


Assuntos
Animais Recém-Nascidos/genética , Cruzamento/métodos , Suínos , Gêmeos Monozigóticos , Animais , Blastocisto/citologia , Células Cultivadas , Embrião de Mamíferos/cirurgia , Feminino , Masculino , Microcirurgia/métodos , Mórula/citologia , Fatores de Tempo
19.
J Bacteriol ; 147(3): 1085-94, 1981 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7275933

RESUMO

Cell-free extracts, membranous fractions, and cell wall preparations from Schizosaccharomyces pombe were examined for the presence of (1 --> 3)-beta-, (1 --> 3)-alpha-, and (1 --> 6)-beta-glucanase activities. The various glucanases were assayed in cells at different growth stages. Only (1 --> 3)-beta-glucanase activity was found, and this was associated with the cell wall fraction. Chromatographic fractionation of the crude enzyme revealed two endo-(1 --> 3)-beta-glucanases, designated as glucanase I and glucanase II. Glucanase I consisted of two subunits of molecular weights 78,500 and 82,000, and glucanase II was a single polypeptide of 75,000. Although both enzymes had similar substrate specificities and similar hydrolytic action on laminarin, glucanase II had much higher hydrolytic activity on isolated cell walls of S. pombe. On the basis of differential lytic activity on cell walls, glucanase II was shown to be present in conjugating cells and highest in sporulating cells. Glucanase II appeared to be specifically involved in conjugation and sporulation since vegetative cells and nonconjugating and nonsporulating cells did not contain this enzyme. The appearance of glucanase II in conjugating cells may be due to de novo enzyme synthesis since no activation could be demonstrated by combining extracts from vegetative and conjugating cells. Increased glucanase activity occurred when walls from conjugating cells were combined with walls from sporulating cells. Studies with trypsin and proteolytic inhibitors suggest that glucanase II exists as a zymogen in conjugating cells. A temperature-sensitive mutant of S. pombe was isolated which lysed at 37 degrees C. Glucanase activity was higher in vegetative cells held at 37 degrees C than cells held at 25 degrees C. Unlike the wild-type strain, this mutant contained glucanase II activity during vegetative growth and may be a regulatory mutant.


Assuntos
Ascomicetos/enzimologia , Schizosaccharomyces/enzimologia , Parede Celular/enzimologia , Conjugação Genética , Ativação Enzimática , Glucana Endo-1,3-beta-D-Glucosidase/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Esporos Fúngicos , Especificidade por Substrato , Temperatura
20.
J Reprod Fertil ; 104(2): 251-8, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7473416

RESUMO

Pig morulae, early blastocysts and blastocysts were microsurgically bisected to produce zona-free demi-embryos or remained nonbisected with or without zona pellucida, and the presence of inner cell mass cells was determined using a differential fluorochrome staining technique. After 24 h of in vitro culture, all demi-embryos were classified into three categories, based on morphological criteria: 1, excellent; 2, fair; and 3, degenerated. The average number of total cells and inner cell mass cells in intact embryos cultured without zona pellucida for 24 h was higher (P < 0.05) than that for those with zona pellucida in morulae and early blastocysts. The percentage of demi-embryos without inner cell mass cells in these different morphological categories was 18.7%, 22.2% and 29.8% for morulae, respectively; 3.8%, 16.7% and 30.8% for early blastocysts, respectively; and 3.7%, 32.0% and 36.4% for blastocysts, respectively. The percentage of demi-embryos without inner cell mass cells was lower (P < 0.01) in demi-embryos classified in category 1 compared with category 3 in early blastocysts and in category 1 compared with categories 2 and 3 in blastocysts. Significant differences in the total number of cells and the number of inner cell mass cells were apparent among the three morphological categories of demi-embryos derived from morulae, early blastocysts and blastocysts. The ratio of total cells to inner cell mass cells was similar among intact pig embryos and the different morphological categories of demi-embryos derived from morulae, early blastocysts and blastocysts, with the exception of that between demi-blastocysts of category 1 and the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Blastocisto/citologia , Embrião de Mamíferos/fisiologia , Trofoblastos/citologia , Animais , Contagem de Células , Corantes , Mórula/citologia , Suínos , Zona Pelúcida
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