Endothelial function, regulation of angiogenesis and embryonic central hemodynamics in ART-conceived pregnancies

This study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, nј39) and normally conceived (control group, nј68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro-antiangiogenic factors balance and increase in vascular impedance in ART-conceived embryos

Nonspecific synaptic plasticity improves the recognition of sparse patterns degraded by local noise

Safaryan, K. et al. Nonspecific synaptic plasticity improves the recognition of sparse patterns degraded by local noise. Sci. Rep. 7, 46550; doi: 10.1038/srep46550 (2017). This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ © The Author(s) 2017.Many forms of synaptic plasticity require the local production of volatile or rapidly diffusing substances such as nitric oxide. The nonspecific plasticity these neuromodulators may induce at neighboring non-active synapses is thought to be detrimental for the specificity of memory storage. We show here that memory retrieval may benefit from this non-specific plasticity when the applied sparse binary input patterns are degraded by local noise. Simulations of a biophysically realistic model of a cerebellar Purkinje cell in a pattern recognition task show that, in the absence of noise, leakage of plasticity to adjacent synapses degrades the recognition of sparse static patterns. However, above a local noise level of 20 %, the model with nonspecific plasticity outperforms the standard, specific model. The gain in performance is greatest when the spatial distribution of noise in the input matches the range of diffusion-induced plasticity. Hence non-specific plasticity may offer a benefit in noisy environments or when the pressure to generalize is strong.Peer reviewe

Heterosynaptic plasticity in the neocortex

Ongoing learning continuously shapes the distribution of neurons’ synaptic weights in a system with plastic synapses. Plasticity may change the weights of synapses that were active during the induction—homosynaptic changes, but also may change synapses not active during the induction—heterosynaptic changes. Here we will argue, that heterosynaptic and homosynaptic plasticity are complementary processes, and that heterosynaptic plasticity might accompany homosynaptic plasticity induced by typical pairing protocols. Synapses are not uniform in their susceptibility for plastic changes, but have predispositions to undergo potentiation or depression, or not to change. Predisposition is one of the factors determining the direction and magnitude of homo- and heterosynaptic changes. Heterosynaptic changes which take place according to predispositions for plasticity may provide a useful mechanism(s) for homeostasis of neurons’ synaptic weights and extending the lifetime of memory traces during ongoing learning in neuronal networks

Search for Production of Invisible Final States in Single-Photon Decays of Υ(1S)Υ(1S)

We search for single-photon decays of the $Υ(1S)$ resonance, $Υ→γ+$ invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson $A^0$, or a pair of dark matter particles, $χ\overline{χ}$. Both $A^0$ and χ are assumed to have zero spin. We tag $Υ(1S)$ decays with a dipion transition $Υ(2S)→π^{+}π^{−}Υ(1S)$ and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range $m_{A^{0}}≤9.2 GeV$ and $m_{χ}≤4.5 GeV$ in the sample of $98×10^{6} Υ(2S)$ decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.Physic

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

From Bulk to Surface Sodium Treatment Reduces Recombination at the Nickel Oxide Perovskite Interface

The effect of sodium doping in NiO as a contact layer for perovskite solar cells is investigated. A combined XRD and XPS analysis reveals that Na mostly segregates as NaOx NaCl species around NiO crystallites, with the effect of reducing interface capacitance as revealed by impedance spectroscopy. Inspired by this finding, we modify the NiO perovskite interface in perovskite solar cells via insertion of an ultra thin NaCl interlayer, which increases the NiO work function by 0.3eV. This leads to an increase of power conversion efficiency, approaching 18 , and open circuit voltage due to a remarkable suppression of surface recombination, as revealed by photoluminescence analysis and light intensity dependent electrical measurement

From Bulk to Surface: Sodium Treatment Reduces Recombination at the Nickel Oxide/Perovskite Interface

The effect of sodium doping in NiO as a contact layer for perovskite solar cells is investigated. A combined X-ray diffraction and X-ray photoelectron spectroscopy analysis reveals that Na+ mostly segregates as NaOx/NaCl species around NiO crystallites, with the effect of reducing interface capacitance as revealed by impedance spectroscopy. Inspired by this finding, the NiO/perovskite interface in perovskite solar cells is modified via insertion of an ultrathin NaCl interlayer, which increases the NiO work-function by 0.3 eV. This leads to an increase of power conversion efficiency, approaching 18%, and open-circuit voltage due to a remarkable suppression of surface recombination, as revealed by photoluminescence analysis and light intensity–dependent electrical measurements