Strong Inhibitory Effects of Antisense Probes on Gene Expression through Ultrafast RNA Photocrosslinking

We have reported the photochemical regulation of the intracellular antisense effect of antisense probes containing a photo‐responsive artificial nucleic acid, 3‐cyanovinylcarbazole nucleoside (^CNVK). Here we focus on the importance of the photocrosslinking rate on the inhibitory effect on gene expression using photocrosslinkable antisense probes (pcASOs). The inhibitory effect of pcASOs on GFP gene expression was dependent on the photocrosslinking rate of 3‐cyanovinylcarbazole with d ‐threoninol (^CNVD), ^CNVK, or psoralen. The ultrafast RNA photocrosslinking induced the formation of a thermally irreversible covalent bond between pcASOs and the target RNA. These ASOs strongly inhibited gene expression only when the photocrosslinking rate was faster than the random walk of branch migration. In addition, pcASOs containing ^CNVD or ^CNVK targeted the RNAs with secondary structures. These results indicate the regulatory effect of photocrosslinker and photoirradiation energy using pcASOs on the gene expression level.     

Finite particle number description of neutron matter using the unitary correlation operator and high-momentum pair methods

Using bare Argonne V4' (AV4'), V6' (AV6'), and V8' (AV8') nucleon–nucleon (\begin{document}$NN$\end{document}) interactions, the nuclear equations of state (EOSs) for neutron matter are calculated with the unitary correlation operator and high-momentum pair methods. Neutron matter is described using a finite particle number approach with magic number \begin{document}$N=66$\end{document} under a periodic boundary condition. The central short-range correlation originating from the short-range repulsion in the \begin{document}$NN$\end{document} interaction is treated by the unitary correlation operator method (UCOM), and the tensor correlation and spin-orbit effects are described by the two-particle two-hole (2p2h) excitations of nucleon pairs, where the two nucleons with a large relative momentum are regarded as a high-momentum (HM) pair. With increasing 2p2h configurations, the total energy per particle of the neutron matter is well-converged under this UCOM+HM framework. Comparing the results calculated with AV4', AV6', and AV8' \begin{document}$NN$\end{document} interactions, we demonstrate the effects of the short-range correlation, tensor correlation, and spin-orbit coupling on the density dependence of the total energy per particle of neutron matter. Moreover, the contribution of each Hamiltonian component to the total energy per particle is discussed. The EOSs of neutron matter calculated within the present UCOM+HM framework agree with the calculations of six microscopic many-body theories, especially the auxiliary field-diffusion Monte Carlo calculations.     

Probe electrospray ionization of mixture solutions using metal needles with different tip conditions

Time-dependent mass spectra of mixture solutions of cytochrome c and cholesterol were measured by probe electrospray ionization (PESI) mass spectrometry and the PESI characteristics for several metal needles were investigated with different tip conditions. For a mixture solution of cytochrome c and cholesterol in 0.1% formic acid methanol/water (1/1) at a motion frequency of 1 Hz, an acupuncture needle with a sharp tip and 0.5-mm-diameter titanium and stainless-steel wire needles gave strong cytochrome c and extremely weak cholesterol ion signals. When the frequency was lowered, and the high-voltage duration increased, the titanium and stainless-steel needles provided both cytochrome c and cholesterol ion signals with high intensities well separated over time.     

Desorption Mass Spectrometry for Nonvolatile Compounds Using an Ultrasonic Cutter

In this work, desorption of nonvolatile analytes induced by friction was studied. The nonvolatile compounds deposited on the perfluoroalkoxy substrate were gently touched by an ultrasonic cutter oscillating with a frequency of 40 kHz. The desorbed molecules were ionized by a dielectric barrier discharge (DBD) ion source. Efficient desorption of samples such as drugs, pharmaceuticals, amino acids, and explosives was observed. The limits of detection for these compounds were about 1 ng. Many compounds were detected in their protonated forms without undergoing significant fragmentation. When the DBD was off, no ions for the neutral samples could be detected, meaning that only desorption along with little ionization took place by the present technique.

High‐Throughput Development of a Hybrid‐Type Fluorescent Glutamate Sensor for Analysis of Synaptic Transmission

Fluorescent sensors are powerful tools for visualizing cellular molecular dynamics. We present a high‐throughput screening system, designated hybrid‐type fluorescence indicator development (HyFInD), to identify optimal position‐specific fluorophore labeling in hybrid‐type sensors consisting of combinations of ligand‐binding protein mutants with small molecular fluorophores. We screened sensors for glutamate among hybrid molecules obtained by the reaction of four cysteine‐reactive fluorescence probes with a set of cysteine‐scanning mutants of the 274 amino acid S1S2 domain of AMPA‐type glutamate receptor GluA2 subunit. HyFInD identified a glutamate‐responsive probe (enhanced glutamate optical sensor: eEOS) with a dynamic range >2400 %, good photostability, and high selectivity. When eEOS was specifically tethered to neuronal surfaces, it reliably visualized the spatiotemporal dynamics of glutamate release at single synapses, revealing synapse‐to‐synapse heterogeneity of short‐term plasticity.     

Performance comparison of bilinear interpolation, bicubic interpolation, and B-spline interpolation in parallel phase-shifting digital holography

To improve the quality of reconstructed images, we apply bicubic interpolation and B-spline interpolation to parallel phase-shifting digital holography for the first time. The effectiveness of bilinear interpolation, bicubic interpolation, and B-spline interpolation in parallel phase-shifting digital holography is shown by a numerical simulation. In the simulation result, the application of bicubic interpolation and B-spline interpolation succeeded in decreasing the rootmean- square error of the reconstructed image by 12.6 and 11.9%, respectively.     

Quark Mass Dependence of the Ground-State Octet Baryons in Next-to-Next-to-Next-to-Leading Order Covariant Baryon Chiral Perturbation Theory

We report on a recent study of the ground-state octet baryon masses using the covariant baryon chiral perturbation theory with the extended-on-mass-shell renormalization scheme up to next-to-next-to-next-to-leading order. By adjusting the available 19 low-energy constants, a good fit of the n _f  = 2 + 1 lattice quantum chromodynamics results from the PACS-CS, LHPC, HSC, QCDSF-UKQCD and NPLQCD collaborations is achieved.     

Reaction of Acetals with Various Carbon Nucleophiles under Non‐Acidic Conditions: C?C Bond Formation via a Pyridinium‐Type Salt

Mild substitution reactions of acetals with carbon nucleophiles via the pyridinium‐type salts generated by the treatment of acetals with TESOTf‐2,4,6‐collidine or 2,2′‐bipyridyl have been developed. Various carbon nucleophiles, such as organocuprates, silyl enol ethers, enamines, etc., reacted with the pyridinium‐type salts to give the corresponding substituted products in good yields. The reactions proceeded under very mild conditions (non‐acidic conditions) and thus acid‐sensitive functional groups can be tolerated during the reaction. In addition, only an acetal can form the pyridinium‐type salt and react with nucleophiles in the presence of a ketal. This unusual selectivity is in contrast to general methods conducted under acidic conditions.