Bright Soliton and Bright–Dark Soliton Pair in an Er-Doped Fiber Laser Mode-Locked Based on In2Se3 Saturable Absorber

The output power in ultrafast fiber lasers is usually limited due to the lack of a versatile saturable absorber with high damage threshold and large modulation depth. Here we proposed a more efficient strategy to improve the output energy of erbium-doped fiber laser based on indium selenide (In2Se3) prepared by using the physical vapor deposition (PVD) method. Finally, stable mode-locked bright pulses and triple-wavelength dark–bright pulse pair generation were obtained successfully by adjusting the polarization state. The average output power and pulse energy were 172.4 mW/101 nJ and 171.3 mW/100 nJ, which are significantly improved compared with the previous work. These data demonstrate that the PVD-In2Se3 can be a feasible nonlinear photonic material for high-power fiber lasers, which will pave a fresh avenue for the high-power fiber laser

Bright 22 μ\mum Excess Candidates from WISE All-Sky Catalog and Hipparcos Main Catalog

In this paper we present a catalog which includes 141 bright candidates ($\leq10.27$ mag, V band) showing the infrared (IR) excess at 22 $\mu$m. Of which, 38 stars are known IR excess stars or disk, 23 stars are double or multiple stars and 4 are Be stars. While the remaining more than 70 stars are identified as the 22 $\mu$m excess candidates in our work. The criterion of selecting candidates is $K_s-[22]_{\mu m}$. All these candidates are selected from \emph{WISE} All-sky data cross-correlated with \emph{Hipparcos} Main Catalog and the likelihood-ratio technique is employed. Considering the effect of background, we introduce the \emph{IRAS} 100 $\mu$m level to exclude the high background. We also estimated the coincidence probability of these sources. In addition, we presented the optical to mid-infrared SEDs and optical images of all the candidates, and gave the observed optical spectra of 6 stars with NAOC's 2.16-m telescope. To measure for the dust amount around each star, the fractional luminosity is also provided. We also test whether our method of selecting IR excess stars can be used to search for extra-solar planets, we cross-matched our catalog with known IR-excess stars having planets but none is matched. Finally, we give the fraction of stars showing IR-excess for different spectral type of main-sequence stars.Comment: 45 pages, 16 figures, 4 tables. Accepted for publication in ApJ

Quantum secure communication scheme with W state

Recently, Cao et al. proposed a new quantum secure direct communication scheme using W state. In their scheme, the error rate introduced by an eavesdropper who takes intercept-resend attack, is only 8.3%. Actually, their scheme is just a quantum key distribution scheme because the communication parties first create a shared key and then encrypt the secret message using one-time pad. We then present a quantum secure communication scheme using three-qubit W state. In our scheme, the error rate is raised to 25% and it is not necessary for the present scheme to use alternative measurement or Bell basis measurement. We also show our scheme is unconditionally secure.Comment: Comments are welcom

Multiparty simultaneous quantum identity authentication based on entanglement swapping

We present a multiparty simultaneous quantum identity authentication protocol based on entanglement swapping. In our protocol, the multi-user can be authenticated by a trusted third party simultaneously

Hydrophobic multiscale cavities for high-performance and self-cleaning surface-enhanced Raman spectroscopy (SERS) sensing

Cavity array, with excellent optical capture capability, has received increasing attention for the surface-enhanced Raman spectroscopy (SERS)-active substrates. Here, we proposed molybdenum disulfide (MoS2) nanocavities growing on pyramid Si (PSi) composed of in situ reduced Au nanoparticles (AuNPs), which can form the multiscale cavities (MSCs), and is facile for the couple of the plasmon. We demonstrated that the PSi/MoS2/Au MSCs can serve as highly sensitive, uniform, and stable SERS substrates for rhodamine 6G (R6G), crystal violet, and adenosine triphosphate detection, benefiting from the synergistic effect of the enhanced light trapping and the effective plasmonic couple. The couple of the plasmon in the MSCs is evidently proved by finite-difference time domain simulation, showing the strong electromagnetic field is located around the cavity wall. Moreover, the excellent hydrophobicity of the PSi/MoS2/AuNPs substrate endows it with the ability for the directional monitoring of organic pollutant in a mixture of oil and water. Finally, we demonstrated the MSCs with outstanding photocatalytic performance could achieve the renewable utilization by self-cleaning, which was attributed to the fast electron transfer and effective light absorption. The proposed PSi/MoS2/AuNPs MSC represents a robust mean using the plasmonic metal/semiconductor heterostructure for high-performance SERS sensors and photodegradation

Quantum broadcast communication

Broadcast encryption allows the sender to securely distribute his/her secret to a dynamically changing group of users over a broadcast channel. In this paper, we just consider a simple broadcast communication task in quantum scenario, which the central party broadcasts his secret to multi-receiver via quantum channel. We present three quantum broadcast communication schemes. The first scheme utilizes entanglement swapping and Greenberger-Horne-Zeilinger state to realize a task that the central party broadcasts his secret to a group of receivers who share a group key with him. In the second scheme, based on dense coding, the central party broadcasts the secret to multi-receiver who share each of their authentication key with him. The third scheme is a quantum broadcast communication scheme with quantum encryption, which the central party can broadcast the secret to any subset of the legal receivers

Gut microbiota-derived endotoxin enhanced the incidence of cardia bifida during cardiogenesis

Background: Cytotoxicity and inflammation-associated toxic responses could be induced by bacterial lipopolysaccharides (LPS) in vitro and in vivo respectively. However, the mechanism involved in LPS-induced cardiac malformation in prenatal fetus is still unknown. Methods and results: In this study, we demonstrated that LPS was induced in gut microbiota imbalance mice, and next, LPS exposure during gastrulation in the chick embryo increased the incidence of cardia bifida. Gene transfection and tissue transplantation trajectory indicated that LPS exposure restricted the cell migration of cardiac progenitors to primary heart field in gastrula chick embryos. In vitro explant allograft of GFP-labeled anterior primitive streak demonstrated that LPS treatments could inhibit cell migration. A similar observation was also obtained from the cell migration assay of scratch wounds using primary culture of cardiomyocytes or H9c2 cells. In the embryos exposed to LPS, expressions of Nkx2.5 and GATA5 were disturbed. These genes are associated with cardiomyocyte differentiation when heart tube fusion occurs. Furthermore, pHIS3, C-caspase3 immunohistological staining indicated that cell proliferation decreased, cell apoptosis increased in the heart tube of chick embryo. Meanwhile, in vivo, pHIS3 immunohistological staining and Hochest/PI staining also draw the similar conclusions. The LPS exposure also caused the production of excess ROS, which might damage the cardiac precursor cells of developing embryos. At last, we showed that LPS-induced cardia bifida could be partially rescued through the addition of antioxidants. Conclusions: Together, these results reveal that excess ROS generation is involved in the LPS-induced defects in heart tube during chick embryo development. This article is protected by copyright. All rights reserve

Coseeded Schwann cells myelinate neurites from differentiated neural stem cells in neurotrophin-3-loaded PLGA carriers

Biomaterials and neurotrophic factors represent promising guidance for neural repair. In this study, we combined poly-(lactic acid-co-glycolic acid) (PLGA) conduits and neurotrophin-3 (NT-3) to generate NT-3-loaded PLGA carriers in vitro. Bioactive NT-3 was released stably and constantly from PLGA conduits for up to 4 weeks. Neural stem cells (NSCs) and Schwann cells (SCs) were coseeded into an NT-releasing scaffold system and cultured for 14 days. Immunoreactivity against Map2 showed that most of the grafted cells (>80%) were differentiated toward neurons. Double-immunostaining for synaptogenesis and myelination revealed the formation of synaptic structures and myelin sheaths in the coculture, which was also observed under electron microscope. Furthermore, under depolarizing conditions, these synapses were excitable and capable of releasing synaptic vesicles labeled with FM1-43 or FM4-64. Taken together, coseeding NSCs and SCs into NT-3-loaded PLGA carriers increased the differentiation of NSCs into neurons, developed synaptic connections, exhibited synaptic activities, and myelination of neurites by the accompanying SCs. These results provide an experimental basis that supports transplantation of functional neural construction in spinal cord injury