5,234 research outputs found
Co-culture of 1-cell outbred mouse embryos on bovine kidney epithelial cells: effect on development, glycolytic activity, inner cell mass: trophectoderm ratios and viability
In an attempt to enhance embryo development, we have co-cultured 1-cell OF1 mouse embryos on bovine kidney epithelial (Madine-Darby bovine kidney; MDBK) cells in a complex medium called complex mouse tubal fluid (cMTF; based on the energy substrate levels found in the mouse oviduct, containing non-essential amino acids, glutamine and EDTA). To determine the quality of the blastocysts obtained, we examined several parameters: morphology, total cell numbers, inner cell mass (ICM): trophectoderm (TE) ratio, glycolytic activity and viability after transfer. A significantly lower number of blastocysts developed on MDBK cells compared with cMTF medium. cMTF blastocysts had a significantly higher glycolytic activity and a lower blastocyst cell number than those grown in co-culture, while both in-vitro groups had higher ICM: TE ratios compared with in vivo. Blastocysts grown on MDBK cells displayed an elevated ICM number compared with those grown in cMTF medium alone. However, the percentage of fetuses after transfer remained drastically low in both culture groups compared with in-vivo blastocysts. In conclusion, co-culture did not increase the number of zygotes reaching the blastocyst stage. Although co-culture blastocysts show some similarities to in-vivo embryos in cell number and glycolytic activity, no enhancement in viability was observe
Spectroscopic Confirmation of a Massive Red-Sequence-Selected Galaxy Cluster at z = 1.34 in the SpARCS-South Cluster Survey
The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a
z'-passband imaging survey, consisting of deep (z' ~ 24 AB) observations made
from both hemispheres using the CFHT 3.6m and CTIO 4m telescopes. The survey
was designed with the primary aim of detecting galaxy clusters at z >~ 1. In
tandem with pre-existing 3.6um observations from the Spitzer Space Telescope
SWIRE Legacy Survey, SpARCS detects clusters using an infrared adaptation of
the two-filter red-sequence cluster technique. The total effective area of the
SpARCS cluster survey is 41.9 deg^2. In this paper, we provide an overview of
the 13.6 deg^2 Southern CTIO/MOSAICII observations. The 28.3 deg^2 Northern
CFHT/MegaCam observations are summarized in a companion paper by Muzzin et al.
(2008). In this paper, we also report spectroscopic confirmation of SpARCS
J003550-431224, a very rich galaxy cluster at z = 1.335, discovered in the
ELAIS-S1 field. To date, this is the highest spectroscopically confirmed
redshift for a galaxy cluster discovered using the red-sequence technique.
Based on nine confirmed members, SpARCS J003550-431224 has a preliminary
velocity dispersion of 1050 +/- 230 km/s. With its proven capability for
efficient cluster detection, SpARCS is a demonstration that we have entered an
era of large, homogeneously-selected z > 1 cluster surveys.Comment: 10 pages, 6 Figures, Submitted to the Ap
A gas sensor system for harsh environment applications
A novel low power, miniature gas sensor measuring system is presented for application in harsh environmental conditions, i.e. to detect carbon monoxide and oxygen at temperatures of up to +225oC and high relative humidities up to 95%. The gas sensors are fabricated using SOI high temperature technology and two full custom ASICs are embedded into a high-temperature circuit board interfaced to a low-cost general purpose microcontroller. The sensor system has been developed for a CO concentration range of 0 to 300 ppm, O2 concentration range of 0 to 21%, and monitors the humidity and temperature of the gas, as well as operating temperatures of micro-heaters within the two MOX gas sensors. Feedback control is built into the program of the micro-controller to compensate for temperature dependence of gas sensors. Preliminary experiments show promising results for the intended application within domestic boilers
Habitual exercise influences carotid artery strain and strain rate, but not cognitive function in healthy middle-aged females
Kinesin-8 molecular motors: putting the brakes on chromosome oscillations
Recent studies suggest that the human Kinesin-8 molecular motor Kif18A has a role in chromosome congression. Specifically, these studies find that Kif18A promotes chromosome congression by attenuating chromosome oscillation magnitudes. Together with recent modeling work, in vitro studies, and the analysis of in vivo yeast data, these reports reveal how Kinesin-8 molecular motors might control chromosome oscillation amplitudes by spatially regulating the dynamic instability of microtubule plus-ends within the mitotic spindle
Births from embryos with highly elevated levels of mitochondrial DNA
Measurement of mtDNA copy number might not provide any advantage in embryo prioritization and could lead to a deselection of blastocysts that would result in healthy pregnancies and births. Furthermore, the quantification of mitochondrial functional output in a model of cellular stress might suggest that mitochondria are not clear targets for biomarker identification as it relates to blastocyst viability. Any suggested link between mtDNA levels, mitochondria or their output with blastocyst transfer outcome requires further validation
Disclosure of Financial Conflicts of Interests in Interventions to Improve Child Psychosocial Health: A Cross-Sectional Study.
Academic journals increasingly request a full disclosure of financial conflict of interest (CoI). The Committee for Publication Ethics provides editors with guidance about the course of action in the case of suspected non-disclosure. No prior study has examined the extent to which journal articles on psychosocial interventions disclose CoI, and how journal editors process requests to examine suspected undisclosed CoI. Four internationally disseminated psychosocial interventions were examined. 136 articles related to an intervention, co-authored by intervention developers and published in health sciences journals were retrieved as requiring a CoI statement. Two editors refused consent to be included in the study. COI disclosures and editor responses were coded for 134 articles. Overall, 92/134 (71%) of all articles were found to have absent, incomplete or partly misleading CoI disclosures. Disclosure rates for the four programs varied significantly between 11% and 73%. Journal editors were contacted about 92 published articles with no CoI disclosure or a disclosure that was considered problematic. In 65/92 (71%) of all cases the editors published an 'erratum' or 'corrigendum'. In 16 of these cases the journal had mishandled a submitted disclosure. The most frequent reason for non-publication of an erratum was that the journal had no disclosure policy at the time of the publication (16 cases). Consumers of research on psychosocial interventions published in peer-reviewed journals cannot currently assume that CoI disclosures are adequate and complete. More efforts are needed to achieve transparency
Improved Chondrogenic Differentiation of rAAV SOX9-Modified Human MSCs Seeded in Fibrin-Polyurethane Scaffolds in a Hydrodynamic Environment
The repair of focal articular cartilage defects remains a problem. Combining gene therapy with tissue engineering approaches using bone marrow-derived mesenchymal stem cells (MSCs) may allow the development of improved options for cartilage repair. Here, we examined whether a three-dimensional fibrin-polyurethane scaffold provides a favorable environment for the effective chondrogenic differentiation of human MSCs (hMSCs) overexpressing the cartilage-specific SOX9 transcription factor via recombinant adeno-associated virus (rAAV) -mediated gene transfer cultured in a hydrodynamic environment in vitro. Sustained SOX9 expression was noted in the constructs for at least 21 days, the longest time point evaluated. Such spatially defined SOX9 overexpression enhanced proliferative, metabolic, and chondrogenic activities compared with control (reporter lacZ gene transfer) treatment. Of further note, administration of the SOX9 vector was also capable of delaying premature hypertrophic and osteogenic differentiation in the constructs. This enhancement of chondrogenesis by spatially defined overexpression of human SOX9 demonstrate the potential benefits of using rAAV-modified hMSCs seeded in fibrin-polyurethane scaffolds as a promising approach for implantation in focal cartilage lesions to improve cartilage repair
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