Superconducting nanowire single-photon detector(SNSPD) has been one of the important ingredients for photonic quantum information processing (QIP). In order to see the potential of SNSPDs, I briefly ...review recent progresses of the photonic QIP with SNSPDs implemented for various purposes and present a possible direction for the development of SNSPDs.
Methods to prevent collisions between people to avoid traffic accidents are receiving significant attention. To measure the position in the non-line-of-sight (NLOS) area, which cannot be directly ...visually recognized, position-measuring methods use wireless-communication-type GPS and propagation characteristics of radio signals, such as received signal strength indication (RSSI). However, conventional position estimation methods using RSSI require multiple receivers, which decreases the position estimation accuracy, owing to the presence of surrounding buildings. This study proposes a system to solve this challenge using a receiver and position estimation method based on RSSI MAP simulation and particle filter. Moreover, this study utilizes BLE peripheral/central functions capable of advertising as the transmitter/receiver. By using the advertising radio waves, our method provides a framework for estimating the position of unspecified transmitters. The effectiveness of the proposed system is evaluated in this study through simulations and experiments in actual environments. We obtained an error average of the distance to be 1.6 m from the simulations, which shows the precision of the proposed method. In the actual environment, the proposed method showed an error average of the distance to be 3.3 m. Furthermore, we evaluated the accuracy of the proposed method when both the transmitter and receiver are in motion, which can be considered as a moving person in the outdoor NLOS area. The result shows an error of 4.5 m. Consequently, we concluded that the accuracy was comparable when the transmitter is stationary and when it is moving. Compared with conventional path loss, the model can measure distances of 3 m to 10 m, whereas the proposed method can estimate the “position” with the same accuracy in an outdoor environment. In addition, it can be expected to be used as a collision avoidance system that confirms the presence of strangers in the NLOS area.
Crystallization and melting are fundamental thermal processes in crystalline polymers. In contrast to recent considerable efforts to simulate molecular processes of crystallization, investigations of ...melting in polymer crystals are still rare. The present report deals with molecular dynamics modeling of melting in chain-folded lamellae of short polyethylene-like molecules made of 100 methylene units. We observe two types of melting with distinct molecular mechanisms: equilibrium melting at the fold surface and nonequilibrium melting at the growth front. The former fold-surface melting is very quick and reversible, giving increasingly thinner lamellae at higher temperatures. Large molecular mobility in the crystal is suggested to be the essential prerequisite for this specific mode of melting. The latter type of melting at the growth front is much slower and irreversible, and it becomes apparent right after the end of rapid surface melting. It is found that the rate of the irreversible melting shows intriguing similarity to the supercooling dependence of the crystallization rate. Large dynamic heterogeneity in the chain-folded crystals is also found, the molecular mechanism of which is closely correlated to the chain conformation at the fold surface. The presence and specific time dependence of solid-state diffusion between different phases (crystalline phase, amorphous phase at the fold surfaces, and isotropic melt phase) are also discussed.
Using light to manipulate materials into desired states is one of the goals in condensed matter physics, since light control can provide ultrafast and environmentally friendly photonics devices. ...However, it is generally difficult to realise a photo-induced phase which is not merely a higher entropy phase corresponding to a high-temperature phase at equilibrium. Here, we report realisation of photo-induced insulator-to-metal transitions in Ta
Ni(Se
S
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including the excitonic insulator phase using time- and angle-resolved photoemission spectroscopy. From the dynamic properties of the system, we determine that screening of excitonic correlations plays a key role in the timescale of the transition to the metallic phase, which supports the existence of an excitonic insulator phase at equilibrium. The non-equilibrium metallic state observed unexpectedly in the direct-gap excitonic insulator opens up a new avenue to optical band engineering in electron-hole coupled systems.
The relationship between genome organization and gene expression has recently been established. However, the relationships between spatial organization, dynamics, and transcriptional regulation of ...the genome remain unknown. In this study, we developed a live-imaging method for simultaneous measurements of the transcriptional activity and nuclear position of endogenous genes, which we termed the 'Real-time Observation of Localization and EXpression (ROLEX)' system. We demonstrated that ROLEX is highly specific and does not affect the expression level of the target gene. ROLEX enabled detection of sub-genome-wide mobility changes that depended on the state of Nanog transactivation in embryonic stem cells. We believe that the ROLEX system will become a powerful tool for exploring the relationship between transcription and nuclear dynamics in living cells.
In frustrated magnetic systems, long-range ordering is forbidden and degeneracy of energy states persists, even at extremely low temperatures. Under certain conditions, these systems form an exotic ...quantum spin-liquid ground state, in which strongly correlated spins fluctuate in the spin lattices. Here we investigate the thermodynamic properties of an anion radical spin liquid of EtMe(3)SbPd(dmit)(2)(2), where dmit represents 1,3-dithiole-2-thione-4,5-dithiolate. This compound is an organic dimer-based Mott insulator with a two-dimensional triangular lattice structure. We present distinct evidence for the formation of a gapless spin liquid by examining the T-linear heat capacity coefficient, γ , in the low-temperature heat capacity. Using comparative analyses with κ-(BEDT-TTF)(2)Cu(2)(CN)(3), a generalized picture of the new spin liquid in dimer-based organic systems is discussed. We also report anomalous enhancement of γ, produced by a kind of criticality inherent to the Pd(dmit)(2) phase diagram.
Genome editing includes various edits of the genome, such as short insertions and deletions, substitutions, and chromosomal rearrangements including inversions, duplications, and translocations. ...These variations are based on single or multiple DNA double‐strand break (DSB)‐triggered in cellulo repair machineries. In addition to these “conventional” genome editing strategies, tools enabling customized, site‐specific recognition of particular nucleic acid sequences have been coming into wider use; for example, single base editing without DSB introduction, epigenome editing with recruitment of epigenetic modifiers, transcriptome engineering using RNA editing systems, and in vitro detection of specific DNA and RNA sequences. In this review, we provide a quick overview of the current state of genome editing and related technologies that multilaterally contribute to cancer science.
In addition to conventional genome editing strategies, tools enabling customized, site‐specific recognition of particular nucleic acid sequences have been coming into wider use; for example, single base editing without DSB introduction, epigenome editing with recruitment of epigenetic modifiers, transcriptome engineering using RNA editing systems, and in vitro detection of specific DNA and RNA sequences. In this review, we provide a quick overview of the current state of genome editing and related technologies that multilaterally contribute to cancer science.
Nitrogen-vacancy (NV) centers in diamond have become an important instrument for quantum sensing and quantum information science. However, the readout of NV spin state requires bulky optical setups, ...limiting fabrication of miniaturized compact devices for practical use. Here we realized photoelectrical detection of magnetic resonance as well as Rabi oscillations on a single-defect level. Furthermore, photoelectrical imaging of individual NV centers at room temperature was demonstrated, surpassing conventional optical readout methods by providing high imaging contrast and signal-to-noise ratio. These results pave the way toward fully integrated quantum diamond devices.
Mechanisms underlying human germ cell development are unclear, partly due to difficulties in studying human embryos and lack of suitable experimental systems. Here, we show that human induced ...pluripotent stem cells (hiPSCs) differentiate into incipient mesoderm-like cells (iMeLCs), which robustly generate human primordial germ cell-like cells (hPGCLCs) that can be purified using the surface markers EpCAM and INTEGRINα6. The transcriptomes of hPGCLCs and primordial germ cells (PGCs) isolated from non-human primates are similar, and although specification of hPGCLCs and mouse PGCs rely on similar signaling pathways, hPGCLC specification transcriptionally activates germline fate without transiently inducing eminent somatic programs. This includes genes important for naive pluripotency and repression of key epigenetic modifiers, concomitant with epigenetic reprogramming. Accordingly, BLIMP1, which represses somatic programs in mice, activates and stabilizes a germline transcriptional circuit and represses a default neuronal differentiation program. Together, these findings provide a foundation for understanding and reconstituting human germ cell development in vitro.
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•Robust induction of hPGCLCs from primed hiPSCs occurs via incipient mesoderm-like cells•EpCAM and INTEGRINα6 are identified as markers for hPGCLC purification•hPGCLCs avoid activation of a somatic program and undergo epigenetic reprogramming•BLIMP1 stabilizes germline transcription and represses neuronal differentiation
Saitou and colleagues report induction of human primordial germ cell-like cells (hPGCLCs) from pluripotent stem cells. hPGCLC and mouse PGC specification rely on similar signaling pathways but utilize distinct transcriptional programs, highlighting differences in PGC induction and demonstrating the utility of hPGCLCs for studying human germ cell development in vitro.
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