Epigenomics Analysis of the Suppression Role of SIRT1 via H3K9 Deacetylation in Preadipocyte Differentiation.

Sirtuin 1 (SIRT1) overexpression significantly inhibits lipid deposition during yak intramuscular preadipocyte (YIMA) differentiation; however, the regulatory mechanism remains unknown. We elucidated the role of SIRT1 in YIMA differentiation using lentivirus-mediated downregulation technology and conducted mRNA-seq and ChIP-seq assays using H3K9ac antibodies after SIRT1 overexpression in order to reveal SIRT1 targets during YIMA adipogenesis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed in order to identify the functional annotation of common genes. In addition, a potential target of SIRT1 was selected to verify its effects on the differentiation and proliferation of YIMAs. SIRT1 interfered with lipid deposition and promoted YIMA differentiation. In total, 143,518 specific peaks were identified after SIRT1 overexpression, where genes associated with downregulation peaks were enriched in transcription, gene expression, lipid-related processes, and classical lipid-related pathways. The H3K9ac signal in the whole genome promoter region (2 kb upstream and downstream of the transcription start site (TSS)) was weakened, and the peaks were distributed across all gene functional regions. Genes that lost signals in their TSS region or gene body region were enriched in both biological processes and pathways associated with lipogenesis. The ChIP-seq results revealed 714 common differential genes in mRNA-seq, which were enriched in "MAPK signaling", "lipid and atherosclerosis", "mTOR signaling", and "FoxO signaling" pathways. A total of 445 genes were downregulated in both their H3K9ac signals and mRNA expression, and one of their most significantly enriched pathways was FoxO signaling. Nine genes (FBP2, FPGT, HSD17B11, KCNJ15, MAP3K20, SLC5A3, TRIM23, ZCCHC10, and ZMYM1) lost the H3K9ac signal in their TSS regions and had low mRNA expression, and three genes (KCNJ15, TGM3, and TRIM54) had low expression but lost their H3K9ac signal in the gene body region. The interference of TRIM23 significantly inhibited fat deposition during preadipocyte differentiation and promoted cell proliferation by increasing S-phase cell numbers. The present study provides new insights into the molecular mechanism of intramuscular fat content deposition and the epigenetic role of SIRT1 in adipocyte differentiation.

Remote preparation and manipulation of squeezed light.

Remote state preparation enables one to create and manipulate a quantum state based on the shared entanglement between distant nodes. Here, we experimentally demonstrate remote preparation and manipulation of squeezed light. By performing a homodyne projective measurement on one mode of the continuous variable entangled state at Alice's station, a squeezed state is created at Bob's station. Moreover, rotation and displacement operations are applied on the prepared squeezed state by changing the projective parameters on Alice's state. We also show that the remotely prepared squeezed state is robust against loss and N - 1 squeezed states can be remotely prepared based on an N-mode continuous variable Greenberger-Horne-Zeilinger-like state. Our results verify the entanglement-based model used in security analysis of quantum key distribution with continuous variables and have potential application in remote quantum information processing.

Experimental Demonstration of Remotely Creating Wigner Negativity via Quantum Steering.

Non-Gaussian states with Wigner negativity are of particular interest in quantum technology due to their potential applications in quantum computing and quantum metrology. However, how to create such states at a remote location remains a challenge, which is important for efficiently distributing quantum resource between distant nodes in a network. Here, we experimentally prepare an optical non-Gaussian state with negative Wigner function at a remote node via local non-Gaussian operation and shared Gaussian entangled state existing quantum steering. By performing photon subtraction on one mode, Wigner negativity is created in the remote target mode. We show that the Wigner negativity is sensitive to loss on the target mode, but robust to loss on the mode performing photon subtraction. This experiment confirms the connection between the remotely created Wigner negativity and quantum steering. As an application, we present that the generated non-Gaussian state exhibits metrological power in quantum phase estimation.

Experimental demonstration of the conversion of local and correlated Gaussian quantum coherence.

Quantum coherence plays an important role in quantum information processing. In this Letter, we experimentally demonstrate the conversion of local and correlated Gaussian quantum coherence in the process of converting two squeezed states into an entangled state. We also investigate the relationship among total, local, and correlated coherence and show that the total coherence of a two-mode Gaussian state is the sum of local quantum coherence of each mode and the correlated quantum coherence between two modes. Our results highlight the connection of different quantum coherence in a two-mode Gaussian system and provide references for potential application.

Copper-Catalyzed Enantioconvergent Cross-Coupling of Racemic Alkyl Bromides with Azole C(sp2 )-H Bonds.

The development of enantioconvergent cross-coupling of racemic alkyl halides directly with heteroarene C(sp2 )-H bonds has been impeded by the use of a base at elevated temperature that leads to racemization. We herein report a copper(I)/cinchona-alkaloid-derived N,N,P-ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp2 )-H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α-chiral alkylated azoles, such as 1,3,4-oxadiazoles, oxazoles, and benzo[d]oxazoles as well as 1,3,4-triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp2 )-H bond and the involvement of alkyl radical species under the reaction conditions.

Deterministic Distribution of Multipartite Entanglement and Steering in a Quantum Network by Separable States.

As two valuable quantum resources, Einstein-Podolsky-Rosen entanglement and steering play important roles in quantum-enhanced communication protocols. Distributing such quantum resources among multiple remote users in a network is a crucial precondition underlying various quantum tasks. We experimentally demonstrate the deterministic distribution of two- and three-mode Gaussian entanglement and steering by transmitting separable states in a network consisting of a quantum server and multiple users. In our experiment, entangled states are not prepared solely by the quantum server, but are created among independent users during the distribution process. More specifically, the quantum server prepares separable squeezed states and applies classical displacements on them before spreading out, and users simply perform local beam-splitter operations and homodyne measurements after they receive separable states. We show that the distributed Gaussian entanglement and steerability are robust against channel loss. Furthermore, one-way Gaussian steering is achieved among users that is useful for further directional or highly asymmetric quantum information processing.

Adaptation of brain functional stream architecture in athletes with fast demands of sensorimotor integration.

Training-induced neuroplasticity has been described in athletes' population. However, it remains largely unknown how regular training and sports proficiency modifies neuronal circuits in the human brain. In this study, we used voxel-based morphometry and stepwise functional connectivity (SFC) analyses to uncover connectivity changes in the functional stream architecture in student-athletes at early stages of sensorimotor skill training. Thirty-two second-year student-athletes whose major was little-ball sports and thirty-four nonathlete controls were recruited for the study. We found that athletes showed greater gray matter volume in the right sensorimotor area, the limbic lobe, and the anterior lobe of the cerebellum. Furthermore, SFC analysis demonstrated that athletes displayed significantly smaller optimal connectivity distance from those seed regions to the dorsal attention network (DAN) and larger optimal connectivity distance to the default mode network (DMN) compared to controls. The Attention Network Test showed that the reaction time of the orienting attention subnetwork was positively correlated with SFC between the seeds and the DAN, while negatively correlated with SFC between the seeds and the DMN. Our findings suggest that neuroplastic adaptations on functional connectivity streams after motor skill training may enable novel information flow from specific areas of the cortex toward distributed networks such as the DAN and the DMN. This could potentially regulate the focus of external and internal attention synchronously in athletes, and consequently accelerate the reaction time of orienting attention in athletes.

Quantum beam splitter for orbital angular momentum of light: quantum correlation by four-wave mixing operated in a nonamplifying regime.

Nondegenerate four-wave mixing (FWM) process based on a double-Λ scheme in hot alkali metal vapor is a versatile tool in quantum state engineering, quantum imaging, and quantum precision measurements. In this Letter, we investigate the generation of quantum correlated twin beams which carry nonzero orbital angular momentums (OAMs) based on the FWM process in hot cesium vapor. The amplified probe beam and the newly generated conjugate beam in the FWM process have the same and opposite topological charge as the seed beam, respectively. We also explore the FWM process operated in a nonamplifying regime where quantum correlated twin beams carrying OAMs can still be generated. In this regime, the FWM process plays the role of quantum beam splitter for the OAM of light; that is, a device that can split a coherent light beam carrying OAM into quantum-correlated twin beams carrying OAMs. More generally, our setup can be used as a quantum beam splitter of images.

Connecting two Gaussian cluster states by quantum entanglement swapping.

Cluster state is an important resource for one-way quantum computation and quantum network. In this paper, we present a scheme for connecting two Gaussian cluster states by entanglement swapping, which can be used to connect two local quantum networks composed by cluster states. The connection schemes between different types of four-mode cluster states are analyzed and we show that the structure of the output states after entanglement swapping may be not the same as that of the input states. The entanglement of the obtained new cluster states are presented when suitable feedforward schemes are applied in the entanglement swapping process. By using optimal gains in the classical channel and inseparability criteria, the requirement of squeezing parameters for obtaining entanglement of output states are reduced. The presented scheme provides a concrete reference for constructing quantum networks with cluster states.

Compact sub-kilohertz low-frequency quantum light source based on four-wave mixing in cesium vapor.

Using a nondegenerate four-wave mixing (FWM) process based on a double-Λ scheme in hot cesium vapor, we demonstrate a compact diode-laser-pumped quantum light source for the generation of quantum correlated twin beams with a maximum squeezing of 6.5 dB. The squeezing is observed at a Fourier frequency in the audio band down to 0.7 kHz which, to the best of our knowledge, is the first observation of sub-kilohertz intensity-difference squeezing in an atomic system so far. A phase-matching condition is also investigated in our system, which confirms the spatial-multi-mode characteristics of the FWM process. Our compact low-frequency squeezed light source may find applications in quantum imaging, quantum metrology, and the transfer of optical squeezing onto a matter wave.

Sustainable Radical Cascades to Synthesize Difluoroalkylated Pyrrolo[1,2-a]indoles.

We disclose herein a photocatalytic difluoroalkylation and cyclization cascade reaction of N-(but-2-enoyl)indoles with broad substrate scopes in up to 90% isolated yield. This method provides sustainable and efficient access to synthesize difluoroalkylated pyrrolo[1,2-a]indoles with a quaternary carbon center under mild conditions.

Closed-Form Algorithm for 3-D Near-Field OFDM Signal Localization under Uniform Circular Array.

Due to its widespread application in communications, radar, etc., the orthogonal frequency division multiplexing (OFDM) signal has become increasingly urgent in the field of localization. Under uniform circular array (UCA) and near-field conditions, this paper presents a closed-form algorithm based on phase difference for estimating the three-dimensional (3-D) location (azimuth angle, elevation angle, and range) of the OFDM signal. In the algorithm, considering that it is difficult to distinguish the frequency of the OFDM signal's subcarriers and the phase-based method is always affected by errors of the frequency estimation, this paper employs sparse representation (SR) to obtain the super-resolution frequencies and the corresponding phases of subcarriers. Further, as the phase differences of the adjacent sensors including azimuth angle, elevation angle and range parameters can be expressed as indefinite equations, the near-field OFDM signal's 3-D location is obtained by employing the least square method, where the phase differences are based on the average of the estimated subcarriers. Finally, the performance of the proposed algorithm is demonstrated by several simulations.

Mixed Incoherent Far-Field and Near-Field Source Localization under Uniform Circular Array.

A high-accuracy algorithm is presented for the localization of mixed incoherent near-field and far-field narrow-band sources under uniform circular array (UCA). Herein, considering that it is difficult to classify the mixed sources, we first decouple mixed sources’ angles and ranges by calculating centro-symmetric sensors’ phase differences. Then, as the phase differences including only sources’ angles can be transformed as indefinite equations, each source’s azimuth angle and elevation angle are obtained by performing the least squares method. After that, on the basis of the estimated angles of the mixed sources, one-dimensional (1-D) multiple signal classification (MUSIC) method and corresponding spatial spectrum are utilized to identify the mixed sources and estimate the ranges of the near-field sources. Finally, simulation and comparison results verify the superior performance of our proposed algorithm.

Quantum random number generator based on twin beams.

We produce two strings of quantum random numbers simultaneously from the intensity fluctuations of the twin beams generated by a nondegenerate optical parametric oscillator. Two strings of quantum random numbers with bit rates up to 60 Mb/s are extracted simultaneously with a suitable post-processing algorithm. By post-selecting the identical data from two raw sequences and using a suitable hash function, we also extract two strings of identical quantum random numbers. The obtained random numbers pass all NIST randomness tests. The presented scheme shows the feasibility of generating quantum random numbers from the intensity of a macroscopic optical field.

Demonstration of Monogamy Relations for Einstein-Podolsky-Rosen Steering in Gaussian Cluster States.

Understanding how quantum resources can be quantified and distributed over many parties has profound applications in quantum communication. As one of the most intriguing features of quantum mechanics, Einstein-Podolsky-Rosen (EPR) steering is a useful resource for secure quantum networks. By reconstructing the covariance matrix of a continuous variable four-mode square Gaussian cluster state subject to asymmetric loss, we quantify the amount of bipartite steering with a variable number of modes per party, and verify recently introduced monogamy relations for Gaussian steerability, which establish quantitative constraints on the security of information shared among different parties. We observe a very rich structure for the steering distribution, and demonstrate one-way EPR steering of the cluster state under Gaussian measurements, as well as one-to-multimode steering. Our experiment paves the way for exploiting EPR steering in Gaussian cluster states as a valuable resource for multiparty quantum information tasks.

Radical Desulfur-Fragmentation and Reconstruction of Enol Triflates: Facile Access to α-Trifluoromethyl Ketones.

We report an efficient oxidative radical desulfur-fragmentation and reconstruction of enol triflates for the synthesis of α-CF3 ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF3 radical from the triflyl group of enol triflate and subsequent addition of the CF3 radical to another enol triflate form the desired α-CF3 ketones. This method provides a new approach to α-CF3 ketones, featuring the utilization of catalytic amount of oxidants, broad substrate scope, and potential to control the regioselectivity.

Quantum Entanglement Swapping between Two Multipartite Entangled States.

Quantum entanglement swapping is one of the most promising ways to realize the quantum connection among local quantum nodes. In this Letter, we present an experimental demonstration of the entanglement swapping between two independent multipartite entangled states, each of which involves a tripartite Greenberger-Horne-Zeilinger (GHZ) entangled state of an optical field. The entanglement swapping is implemented deterministically by means of a joint measurement on two optical modes coming from the two multipartite entangled states respectively and the classical feedforward of the measurement results. After entanglement swapping the two independent multipartite entangled states are merged into a large entangled state in which all unmeasured quantum modes are entangled. The entanglement swapping between a tripartite GHZ state and an Einstein-Podolsky-Rosen entangled state is also demonstrated and the dependence of the resultant entanglement on transmission loss is investigated. The presented experiment provides a feasible technical reference for constructing more complicated quantum networks.

Remote transfer of Gaussian quantum discord.

Quantum discord quantifies quantum correlation between quantum systems, which has potential application in quantum information processing. In this paper, we propose a scheme realizing the remote transfer of Gaussian quantum discord, in which another quantum discordant state or an Einstein-Podolsky-Rosen entangled state serves as ancillary state. The calculation shows that two independent optical modes that without direct interaction become quantum correlated after the transfer. The output Gaussian quantum discord can be higher than the initial Gaussian quantum discord when optimal gain of the classical channel and the ancillary state are chosen. The physical reason for this result comes from the fact that the quantum discord of an asymmetric Gaussian quantum discordant state can be higher than that of a symmetric one. The presented scheme has potential application in quantum information network.

The protease Lon prolongs insect lifespan by responding to reactive oxygen species and degrading mitochondrial transcription factor A.

Diapause is a widespread adaptation of insects that enables them to survive during unfavorable seasons and is characterized by suppressed metabolism and increased lifespan. Previous works have demonstrated that high levels of reactive oxygen species (ROS) and hypoxia-inducible factor-1α (HIF-1α) in the pupal brain of the moth Helicoverpa armigera induce diapause and extend lifespan by downregulating mitochondrial transcription factor A (TFAM). However, the molecular mechanisms of ROS-HIF-1α regulating metabolic activity to extend lifespan are still poorly understood. Here, we show that the mitochondrial abundance in diapause-type pupal brains is markedly lower than that in their nondiapause-type pupae, suggesting that ROS-HIF-1α signaling negatively regulates the number of mitochondria. The protease Lon, a major mitochondrial matrix protease, can respond to ROS signals. It is activated by transcription factor HIF-1α, which specifically binds the LON promoter to promote its expression. A high level of LON mediates the degradation of TFAM, which is a crucial factor in regulating mitochondrial abundance and metabolic activity. We believe this is the first report that a previously unrecognized regulatory pathway, ROS-HIF-1α-LON-TFAM, reduces mitochondrial activity to induce diapause, extending insect lifespan.

ROS elevate HIF-1α phosphorylation for insect lifespan through the CK2-MKP3-p38 pathway.

Diapause in insects is akin to dauer in Caenorhabditis elegans and hibernation in vertebrates, characterized by metabolic depression and lifespan extension. Previous studies have shown that reactive oxygen species (ROS) and hypoxia-inducible factor-1α (HIF-1α) in brains of diapause-destined pupae are more abundant than those in nondiapause-destined pupae in Helicoverpa armigera, but the ROS regulating HIF-1α activity remain unknown. Here, we showed that high ROS levels in brains of diapause-destined pupae resulted in low casein kinase 2 (CK2) activity and that downregulation of CK2 caused low expression of mitogen-activated protein kinase phosphatase 3 (MKP3), which is an inhibitor of p-p38. Thus, high p-p38 levels accumulate to improve HIF-1α activity via activating HIF-1α phosphorylation at the S732 residue to regulate insect diapause. This is the first report showing that a new pathway, ROS-CK2-MKP3-p38, regulates HIF-1α activity for lifespan in insects.