Identification of myoelectric signals of pregnant rat uterus: new method to detect myometrial contraction

Aim To develop an electromyography method for pregnant rat uterus in vivo and to separate myometrial signals from the gastrointestinal tract signals. Methods: Pregnant Sprague-Dawley rats (n = 8) were anaesthetized and their stomach, small intestine, and large intestine were removed from the abdomen. A pair of thread electrodes was inserted into the uterus, while a pair of disk electrodes was placed subcutaneously above the myometrium. Additionally, a strain gauge sensor was fixed on the surface of the myometrium and cecum for the parallel detection of mechanical contractions in rats (n = 18) with intact gastrointestinal tract. The filtered electric signals were amplified and recorded by an online computer system and analyzed by fast Fourier transformation. The frequency of the electric activity was characterized by cycle per minute (cpm), the magnitude of the activity was described as power spectrum density maximum (PsDmax). Results: The frequency of the pregnant uterine activity was 1-3 cpm, which falls within the same range as that of cecum. Measuring by both electrodes, oxytocin (1 μg/kg) increased and terbutaline (50 μg/kg) decreased the PsDmax by 25%-50% (P < 0.001) and 25%-40% (P < 0.01), respectively. We found a strong positive correlation between the alterations of PsDmax values and the strain gauge sensordetected mechanical contractions (area under curve). The GI specific compounds (neostigmine, atropine) mainly affected the cecal activity, while myometrium specific drugs (oxytocin, terbutaline) influenced the myometrial signals only. Conclusion: Our method proved to be able to detect the myoelectric activity that reflects the mechanical contraction. The overlapping myometrial and cecal signals are not separable, but they can be distinguished based on the much higher activity and different pharmacological reactivity of the pregnant uterus. Thus, the early signs of contractions can be detected and labor may be predicted in a fast and sensitive way

Cinchona based squaramide catalysed enantioselective Michael addition of a-nitrophosphonates to aryl acrylates: enantioselective synthesis of quaternary a-aminophosphonates

Several cinchona based squaramide catalysts were applied to the asymmetric Michael addition of α-nitroethylphosphonates to acrylic acid aryl esters, resulting in high yields and enantioselectivities. The absolute configuration of one of the quaternary α-nitrophosphonate adducts was deduced from its experimental and calculated CD spectra. The adducts were reduced to their cyclic aminophosphonates by catalytic hydrogenation

Numerical modeling of mantle convection in 3D on the SEE-GRID-SCI infrastructure

The Numerical Modeling of Mantle Convection (NMMC3D) application is calculating mantle convection models in 3D Cartesian domain. Our main goal is to study the structure and the surface manifestation (topographic and geoid anomalies) of the mantle plumes. The parameter study support tools of the P-GRADE grid Portal give an effective possibility to make an systematic investigation of the parameters influencing the character of mantle plumes. In collaboration with the MTA SZTAKI Application Porting Centre the NMMC3D has been ported to the SEE-GRID-SCI infrastructure. The paper introduces the steps that were taken to enable NMMC3D application on gLite based grid infrastructure and some results of the calculations. The main parameters influencing the mantle convection are the Rayleigh-number and the viscosity distribution of the mantle. This paper focuses the effect of these parameters on the thermal structure and surface manifestations of mantle plumes

Large-area nanoengineering of graphene corrugations for visible-frequency graphene plasmons

Quantum confinement of graphene carriers is an effective way to engineer its properties. It is commonly realized through physical edges that are associated with the deterioration of mobility and strong suppression of plasmon resonances. Here, we demonstrate a simple, large-area, edge-free nanostructuring technique, based on amplifying random nanoscale structural corrugations to a level where they efficiently confine carriers, without inducing significant inter-valley scattering. This soft confinement, allows the low-loss lateral ultra-confinement of graphene plasmons, scaling up their resonance frequency from native terahertz to commercially relevant visible range. Visible graphene plasmons localized into nanocorrugations mediate several orders of magnitude stronger light-matter interactions (Raman enhancement) than those previously achieved with graphene, enabling the detection of specific molecules from femtomolar solutions or ambient air. Moreover, nanocorrugated graphene sheets also support propagating visible plasmon modes revealed by scanning near-field optical microscopy observation of their interference patterns