395 research outputs found

    IGF-1/IGFBP-1 increases blastocyst formation and total blastocyst cell number in mouse embryo culture and facilitates the establishment of a stem-cell line

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    BACKGROUND: Apoptosis occurs frequently for blastocysts cultured in vitro, where conditions are suboptimal to those found in the natural environment. Insulin-like growth factor-1 (IGF-1) plays an important role in preventing apoptosis in the early development of the embryo, as well as in the progressive regulation of organ development. We hypothesize that IGF-1 and its dephosphorylated binding protein (IGFBP-1) may be able to improve embryo culture with an associated reduced cell death, and that the resultant increase in the total cell number of the embryo could increase the chances of establishing an embryonic stem-cell line. RESULTS: In vivo fertilized zygotes were cultured in medium containing supplementary IGF-1, or IGFBP-1/IGF-1. The stages of the resultant embryos were evaluated at noon on day five post-hCG injection. The extent of apoptosis and necrosis was evaluated using Annexin V and propidium iodine staining under fluorescent microscopy. The establishment of embryonic stem-cell lines was performed using the hatching blastocysts that were cultured in the presence of IGF-1 or IGFBP-1/IGF-1. The results show that the rate of blastocyst formation in a tissue-culture system in the presence of IGF-1 was 88.7% and IGFBP-1/IGF-1 it was 94.6%, respectively, and that it was significantly greater than the figure for the control group (81.9%). IGFBP-1/IGF-1 also resulted in a higher hatching rate than was the case for the control group (68.8% vs. 48.6% respectively). IGF-1 also increased the number of Annexin V-free and propidium iodine-free blastocysts in culture (86.8% vs. 75.9% respectively). Total cell number of blastocyst in culture was increased by 18.9% for those examples cultured with dephosphorylated IGFBP-1/IGF-1. For subsequent stem-cell culture, the chances of the successful establishment of a stem-cell line was increased for the IGF-1 and IGFBP-1/IGF-1 groups (IGF-1 vs. IGFBP-1/IGF-1 vs. control: 45.8% vs. 59.6% vs. 27.3% respectively). CONCLUSION: IGF-1 or dephosphorylated IGFBP-1/IGF-1 supplement does result in an anti-apoptotic effect for early embryo development in culture, with a subsequent increased total cell number resulting from cell culture. The effect is beneficial for the later establishment of a stem-cell line

    Fabrication of multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors by using CF4 plasma treatment

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    Multianalyte CeO2 biosensors have been demonstrated to detect pH, glucose, and urine concentrations. To enhance the multianalyte sensing capability of these biosensors, CF4 plasma treatment was applied to create nanograin structures on the CeO2 membrane surface and thereby increase the contact surface area. Multiple material analyses indicated that crystallization or grainization caused by the incorporation of flourine atoms during plasma treatment might be related to the formation of the nanograins. Because of the changes in surface morphology and crystalline structures, the multianalyte sensing performance was considerably enhanced. Multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors exhibit potential for use in future biomedical sensing device applications

    Epinephrine administration via a laryngeal mask airway: what is the optimal dose?

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    Background. The aim of this animal study was to clarify the effects of laryngeal mask airway (LMA)-administrated epinephrine and to assess the optimal dose. Methods. Thirty pigs were anesthetized and intubated with a cuffed tracheal tube (TT) and an LMA. Then they were assigned to one of five groups. The control group received distilled water 10 mL via the TT; the TT group received epinephrine 50 μg/kg via the TT; and the other three groups received two, four or six times the TT dose of epinephrine via the LMA. Heart rate (HR) and arterial pressure were monitored before and after drug administration for 15 minutes. Results. After epinephrine administration, the LMA-6 and TT groups had elevated systolic, diastolic and mean arterial pressures at 1 min and there was no significant difference between the two groups. In the TT group, these parameters peaked at 2 min then declined rapidly. In the LMA-6 group, they increased more slowly, and then maintained a plateau. The control, LMA-2 and LMA-4 groups failed to display significant persistent (>2 min) hemodynamic changes. Conclusions. We could not identify an optimal LMA-administrated epinephrine dose. The TT route is suitable when a high peak drug effect is required and the LMA route may be preferable if a persistent plateau effect is desired. Effective LMA administration of drugs may require larger doses than those given via TT

    Spatial distribution of job opportunities in China: Evidence from the opening of the high-speed rail

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The provision of sufficient job opportunities has traditionally been a primary objective for both local and central governments. In response to this concern, we investigate spatial dependence of job opportunities among 30 Chinese provincial capital cities (PCCs) from 2002 to 2016, giving special attention to the spatial spillovers of the opening of the high-speed rail (HSR). Using appropriate spatial panel data models, our findings suggest the presence of significant spatial autocorrelation of job opportunities among PCCs. Whilst the HSR has been found to increase job opportunities at the national level, which, however, is not confirmed at the regional level. The spatial spillover effects of the HSR are significant and positive only in the eastern/northeastern region. These findings can help the central government to more fully understand spatial dependence of job opportunities, better plan future HSR networks, and efficiently allocate transportation resources, encouraging cross-regional collaboration to promote regional employment

    Cluster Analysis of the Ising Model and Universal Finite-Size Scaling

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    The recent progress in the study of finite-size scaling (FSS) properties of the Ising model is briefly reviewed. We calculate the universal FSS functions for the Binder parameter gg and the magnetization distribution function p(m)p(m) for the Ising model on L1×L2L_1 \times L_2 two-dimensional lattices with tilted boundary conditions. We show that the FSS functions are universal for fixed sets of the aspect ratio L1/L2L_1/L_2 and the tilt parameter. We also study the percolating properties of the Ising model, giving attention to the effects of the aspect ratio of finite systems. We elucidate the origin of the complex structure of p(m)p(m) for the system with large aspect ratio by the multiple-percolating-cluster argument.Comment: 11 pages including 6 eps figures, elsart.sty, to appear in Physica

    Proteinlike behavior of a spin system near the transition between ferromagnet and spin glass

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    A simple spin system is studied as an analog for proteins. We investigate how the introduction of randomness and frustration into the system effects the designability and stability of ground state configurations. We observe that the spin system exhibits protein-like behavior in the vicinity of the transition between ferromagnet and spin glass. Our results illuminate some guiding principles in protein evolution.Comment: 12 pages, 4 figure

    3,3′-Di-n-butyl-1,1′-(p-phenyl­ene­dimethyl­ene)diimidazolium bis­(hexa­fluoro­phosphate)

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    The asymmetric unit of the title N-heterocyclic carbene compound, C22H32N4 2+·2PF6 −, consists of one half of the N-heterocyclic carbene dication and one hexa­fluoro­phosphate anion. The dication lies across a crystallographic inversion center. The imidazole ring is twisted away from the central benzene ring, making a dihedral angle of 76.23 (6)°. The hexa­fluoro­phosphate anions link the cations into a three-dimensional network via inter­molecular C—H⋯F hydrogen bonds. A weak C—H⋯π inter­action further stabilizes the crystal structure
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