Differential effect of denervation on free radical scavenging enzymes in slow and fast muscle of rat

To determine the effect of denervation on the free radical scavenging systems in relation to the mitochondrial oxidative metabolism in the slow twitch soleus and fast twitch extensor digitorum longus (EDL) muscles, the sciatic nerve of the rat was crushed in the mid-thigh region and the muscle tissue levels of 5 enzymes were studied 2 and 5 weeks following crush. Radioimmunoassays were utilized for the selective measurement of cuprozinc (cytosolic) and mangano (mitochondrial) superoxide dismutases. These data represent the first systematic report of free radical scavening systems in slow and fast muscles in response to denervation. Selective modification of cuprozinc and manganosuperoxide dismutases and differential regulation of GSH-peroxidase was demonstrated in slow and fast muscle

Home Blood Pressure Monitoring: New Evidence for an Expanded Role

In a Perspective, Mark Caulfield discusses potential implications of using home blood pressure monitoring for diagnosis and treatment of hypertension. Please see later in the article for the Editors' Summar

Unconventional Superconductivity and Electron Correlations in Cobalt Oxyhydrate Na0.35_{0.35}CoO2_{2}⋅y\cdot yH2_{2}O

We report a precise $^{59}$Co nuclear quadrupolar resonance (NQR) measurement on the recently discovered cobalt oxyhydrate Na$_{0.35}$CoO$_{2}$$\cdot y$H$_{2}$O superconductor from $T$=40 K down to 0.2 K. We find that in the normal state the spin-lattice relaxation rate $1/T_1$ follows a Curie-Weiss type temperature ($T$) variation, $1/T_1T=C/(T-\theta)$, with $\theta$=-42 K, suggesting two-dimensional antiferromagnetic spin correlations. Below $T_c$=3.9 K, $1/T_1$ decreases with no coherence peak and follows a $T^n$ dependence with $n\simeq$2.2 down to $\sim$2.0 K but crosses over to a $1/T_1\propto T$ variation below $T$=1.4 K, which suggests non s-wave superconductivity. The data in the superconducting state are most consistent with the existence of line nodes in the gap function.Comment: submitted for publication in June '0

Inhomogeneous electronic structure probed by spin-echo experiments in the electron doped high-Tc superconductor Pr_{1.85}Ce_{0.15}CuO_{4-y}

63Cu nuclear magnetic resonance (NMR) spin-echo decay rate (T_2^{-1}) measurements are reported for the normal and superconducting states of a single crystal of Pr_{1.85}Ce_{0.15}CuO_{4-y} (PCCO) in a magnetic field B_0=9T over the temperature range 2K<T<200K. The spin-echo decay rate is temperature-dependent for T<55K, and has a substantial dependence on the radio frequency (rf) pulse parameters below T~25K. This dependence indicates that T_2^{-1} is strongly effected by a local magnetic field distribution that can be modified by the rf pulses, including ones that are not at the nuclear Larmor frequency. The low-temperature results are consistent with the formation of a static inhomogeneous electronic structure that couples to the rf fields of the pulses.Comment: 4 pages, 4 figure

Heavy-Fermion Formation at the Metal-to-Insulator Transition in Gd1−x_{1-x}Srx_xTiO3_3

The perovskite-like transition-metal oxide Gd$_{1-x}$Sr$_x$TiO$_3$ is investigated by measurements of resistivity, specific-heat, and electron paramagnetic resonance (EPR). Approaching the metal-to-insulator transition from the metallic regime ($x \geq 0.2$), the Sommerfeld coefficient $\gamma$ of the specific heat becomes strongly enhanced and the resistivity increases quadratically at low temperatures, which both are fingerprints of strong electronic correlations. The temperature dependence of the dynamic susceptibility, as determined from the Gd$^{3+}$-EPR linewidth, signals the importance of strong spin fluctuations, as observed in heavy-fermion compounds.Comment: 4pages, 3 figure

Evidence for the formation of magnetic moments in the cuprate superconductor Hg0.8_{0.8}Cu0.2_{0.2}Ba2_2Ca2_2Cu3_3O8+δ_{8+\delta} below TcT_c seen by NQR

We report pure zero field nuclear magnetic resonance (NQR) measurements on the optimally doped three layer high-$T_{c}$-compounds HgBaCaCuO and HgBaCaCuO(F) with $T_c$ 134 K. Above $T_{c}$ two Cu NQR line pairs are observed in the spectra corresponding to the two inequivalent Cu lattice sites. Below $T_{c}$ the Cu NQR spectra show additional lines leading to the extreme broadened Cu NQR spectra at 4.2 K well known for the HgBaCaCuO compounds. The spin-lattice relaxation curves follow a triple exponential function with coefficients depend onto the saturation time (number of saturation pulses), whereas the spin-spin relaxation curve is described by a single exponential function. From the spin-lattice relaxation we deduced a complete removal of the Kramers degeneracy of the Cu quadrupole indicating that the additional lines are due to a Zeemann splitting of the $^{63/65}$Cu lines due to the spontaneous formation of magnetic moments within the CuO layers. Below 140 K, the spectra are well fitted by a number of 6 $^{63/65}$Cu line pairs. From the number of the Cu lines, the position of the lines relative to each other and the complete removal of the Kramers degeneracy we deduced an orientation of the magnetic moments parallel to the symmetry axis of the electric field gradient tensor with magnitudes of the order of 1000 G. We also discuss the possible microscopic origin of the observed internal magnetic fields.Comment: 11 pages, 12 figure

Alternative, but expensive, energy transition scenario featuring carbon capture and utilization can preserve existing energy demand technologies

To reach net-zero carbon emissions, most climate change mitigation scenarios model a rapid transition from hydrocarbon-based energy to renewables, wide-scale electrification, and offsets to mitigate residual emissions. This requires phasing out existing hydrocarbon infrastructure and adjustments to electrification. Carbon capture and utilization (CCU) to produce synthetic fuels could be an alternative way to reach net zero while maintaining some existing energy infrastructure and minimizing the societal transition required, yet such scenarios remain unexamined. Here, we analyzed a CCU-based net-zero emissions scenario using a global energy system model. We find that synthetic fuel could meet 30% of energy demand by 2050, resulting in maintaining some existing technologies in energy demand sectors. Meanwhile, this scenario requires rapid upscaling of non-biomass renewables and direct air capture. The CCU-based scenario could be an alternative pathway; however, it involves multiple challenges related to technological feasibility and increased mitigation costs relative to net-zero scenarios using renewables, bioenergy, and carbon dioxide removal