Radio observations of several interstellar molecules.

We present observations of rotational transitions for several interstellar molecules whose formation may be related to grain processes and discuss their implications for interstellar chemistry. Interstellar hydrogen sulfide has been observed at fractional abundances f(H\sb2S) $\sim$ 10\sp{-9} relative to H\sb2 towards cold, dark clouds, while its abundance is enhanced by a factor of 1000 in the Orion hot core and the plateau. H\sb2S may be evaporating from the grain mantles in the hot core, and even in the cold, dark clouds, grain surface reactions may be responsible for the gas-phase H\sb2S abundances. We also derive an upper limit for the HDS abundance (HDS) / (H\sb2S) $\leq$ 6 $\times$ 10\sp{-4} in the Orion hot core. H\sb2CS ortho-to-para ratios have been observed to be $\sim$1.8 towards TMC-1, which may suggest that H\sb2CS is in equilibrium with the expected grain temperature (10 K) and gas-grain exchanges are taking place effectively in cold, dark clouds. We derive a ratio of $\sim$3, the statistical value, for Orion(3N1E) and NGC7538, and $\sim$2 for Orion(KL). We derive upper limits of the ethyl cyanide column densities of $\sim$3 $\times$ 10\sp{12} cm\sp{-2} towards TMC-1 and L134N. Together with the detection for vinyl cyanide, there may be no necessity of invoking grain surface synthesis for these highly saturated species in cold clouds, but the desorption processes seem to be quite inefficient for these heavy molecules. Finally, we have surveyed HOCO\sp+ as a tracer of interstellar CO\sb2 towards many galactic sources, and derive f(HOCO\sp+) $\sim$ 10\sp{-8} - 10\sp{-9} in the Galactic center and $\leq$10\sp{-10} for cold dark clouds. The observed abundance of HOCO\sp+ in the Galactic center is $\sim$3 and $\sim$1 orders of magnitude larger than that predicted by ion-molecule chemistry and shock chemistry, respectively. UV photolysis of grain mantles may produce CO\sb2 efficiently, resulting in a large abundance of HOCO\sp+ in the Galactic center. Interstellar grains are thought to play crucial roles in the chemistry of interstellar molecular clouds, and our results give some constraints on the highly uncertain grain processes, as well as on the gas phase processes

Optimal State Transfer and Entanglement Generation in Power-law Interacting Systems

We present an optimal protocol for encoding an unknown qubit state into a multiqubit Greenberger-Horne-Zeilinger-like state and, consequently, transferring quantum information in large systems exhibiting power-law ($1/r^\alpha$) interactions. For all power-law exponents $\alpha$ between $d$ and $2d+1$, where $d$ is the dimension of the system, the protocol yields a polynomial speedup for $\alpha>2d$ and a superpolynomial speedup for $\alpha\leq 2d$, compared to the state of the art. For all $\alpha>d$, the protocol saturates the Lieb-Robinson bounds (up to subpolynomial corrections), thereby establishing the optimality of the protocol and the tightness of the bounds in this regime. The protocol has a wide range of applications, including in quantum sensing, quantum computing, and preparation of topologically ordered states. In addition, the protocol provides a lower bound on the gate count in digital simulations of power-law interacting systems.Comment: Updated Table I, Additional discussion on a lower bound for the gate count in digital quantum simulatio

Automated electrophysiological and pharmacological evaluation of human pluripotent stem cell-derived cardiomyocytes

Automated planar patch clamp systems are widely used in drug evaluation studies because of their ability to provide accurate, reliable, and reproducible data in a high-throughput manner. Typically, CHO and HEK tumorigenic cell lines overexpressing single ion channels are used since they can be harvested as high-density, homogenous, single-cell suspensions. While human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) are physiologically more relevant, these cells are fragile, have complex culture requirements, are inherently heterogeneous, and are expensive to produce, which has restricted their use on automated patch clamp (APC) devices. Here, we used high efficiency differentiation protocols to produce cardiomyocytes from six different hPSC lines for analysis on the Patchliner (Nanion Technologies GmbH) APC platform. We developed a two-step cell preparation protocol that yielded cell catch rates and whole-cell breakthroughs of ∼80%, with ∼40% of these cells allowing electrical activity to be recorded. The protocol permitted formation of long-lasting (>15 min), high quality seals (>2 GΩ) in both voltage- and current-clamp modes. This enabled density of sodium, calcium, and potassium currents to be evaluated, along with dose–response curves to their respective channel inhibitors, tetrodotoxin, nifedipine, and E-4031. Thus, we show the feasibility of using the Patchliner platform for automated evaluation of the electrophysiology and pharmacology of hPSC-CMs, which will enable considerable increase in throughput for reliable and efficient drug evaluation