Optical ReLU-like activation function based on a semiconductor laser with optical injection.

Artificial neural networks usually consist of successive linear multiply-accumulate operations and nonlinear activation functions. However, most optical neural networks only achieve the linear operation in the optical domain, while the optical implementation of activation function remains challenging. Here we present an optical ReLU-like activation function (with 180° rotation) based on a semiconductor laser subject to the optical injection in an experiment. The ReLU-like function is achieved in a broad regime above the Hopf bifurcation of the injection-locking diagram and is operated in the continuous-wave mode. In particular, the slope of the activation function is reconfigurable by tuning the frequency difference between the master laser and the slave laser.

Asynchronous photonic time-delay reservoir computing.

Time-delay reservoir computing uses a nonlinear node associated with a feedback loop to construct a large number of virtual neurons in the neural network. The clock cycle of the computing network is usually synchronous with the delay time of the feedback loop, which substantially constrains the flexibility of hardware implementations. This work shows an asynchronous reservoir computing network based on a semiconductor laser with an optical feedback loop, where the clock cycle (20 ns) is considerably different to the delay time (77 ns). The performance of this asynchronous network is experimentally investigated under various operation conditions. It is proved that the asynchronous reservoir computing shows highly competitive performance on the prediction task of Santa Fe chaotic time series, in comparison with the synchronous counterparts.

Novel Fluorescent Probe toward Fe3+ Based on Rhodamine 6G Derivatives and Its Bioimaging in Adult Mice, Caenorhabditis elegans, and Plant Tissues.

A new fluorescent probe LXY based on the rhodamine 6G platforms has been designed, synthesized, and characterized, which could recognize Fe3+ effectively in HEPES buffer (10 mM, pH = 7.4)/CH3CN (2:3, v/v). And the distinct color change and the rapid emergence of fluorescence emission at 550 nm achieved "naked eye" detection of Fe3+. The interaction mode between them was achieved by Job's plot, MS, SEM, and X-ray single-crystal diffraction. Importantly, the crystal structures proved that Fe3+ could induce the rhodamine moiety transform the closed-cycle form to the open-cycle form. But it is interesting that Fe3+ did not appear in the crystal structures. Meanwhile, the limit of detection (LOD) of LXY to Fe3+ was calculated to be 3.47 × 10-9. In addition, the RGB experiment, test papers, and silica gel plates all indicated that the probe LXY could be used to distinguish Fe3+ quantitatively and qualitatively on-site. Moreover, the probe LXY has also been successfully applied to Fe3+ image in Caenorhabditis elegans, adult mice, and plant tissues. Thus, LXY was considered to have some potential for application in bioimaging.

A Coumarin-Based Fluorescent Probe for Ratiometric Detection of Cu2+ and Its Application in Bioimaging.

The fluorescent probe L, based on naphthalimide-modified coumarin, was designed, synthesized, and characterized, which could recognize Cu2+ from other cations selectively and sensitively in HEPES buffer (10 mM, Ph = 7. 4)/CH3CN (1:4, V/V). When the probe L interacted with Cu2+, the color and the fluorescent intensity changed obviously and it provided the naked-eye detection for Cu2+. The recognition mode between them was achieved by Job's plot, IR, MS, SEM, and 1HNMR. In addition, test strips made from L could still interact with Cu2+ in tap water effectively. The limit of detection (LOD) of L was 3.5 × 10-6 M. Additionally, the density functional theory (DFT) calculation method was used to analyze the action mechanism of L toward Cu2+. Importantly, the fluorescent probe L could demonstrate favorable selectivity toward Cu2+ in Caenorhabditis elegans. Thus, L was considered to have some potential for application in bioimaging.

Overexpression of lncRNA ANRIL promoted the proliferation and migration of prostate cancer cells via regulating let-7a/TGF-ß1/ Smad signaling pathway.

Long non-coding RNAs (lncRNAs) were playing critical roles in tumorigenesis. However, in prostate cancer, the roles and mechanisms of lncRNAs especially ANRIL were largely unknown. We investigated the effects of ANRIL on the proliferation and migration of prostate cancer cells using CCK-8 assay and Transwell migration assay. Real-time PCR and western blotting assays were used to analyze the levels of ANRIL, let-7a, TGF-ß1, p-Smad2 and p-Smad7. Our results showed that ANRIL was significantly overexpressed in prostate cancer tissues compared with corresponding normal tissues. Knockdown of ANRIL significantly inhibited the proliferation and migration of prostate cancer LNCap, PC3 and DU145 cells. Knockdown of ANRIL significantly decreased the levels of TGF-ß1 and p-Smad2, and increased the level of p-Smad7 in prostate cancer LNCap cells. We further found that knockdown of ANRIL significantly enhanced the expression of let-7a, and rescue experiment found that let-7a inhibitor recovered the suppressive effects of ANRIL silencing on the proliferation and migration of prostate cancer LNCap, PC3 and DU145 cells. And let-7a inhibitor recovered the suppressive effects of ANRIL silencing on the activity of TGF-ß1/Smad signaling pathway in prostate cancer LNCap cells. Taken together, our findings indicated that overexpression of lncRNA ANRIL promoted the proliferation and migration of prostate cancer cells via regulating let-7a/TGF-ß1/Smad signaling pathway.

[Genetic diversity of 21 Fusarium strains in Section Martiella based on ISSR analysis].

In order to understand the genetic difference and phylogenic relationship within and among the Fusarium species in Section Martiella, the genetic diversity of 21 Fusarium strains in the section was examined by inter-simple sequence repeats (ISSR). Fifteen selected ISSR primers were adopted to do amplification, and a total of 239 bands were amplified, among which, 230 (96.2%) were polymorphic, with an average of 15.3 polymorphic bands per primer. The genetic similarity ranged from 0.494 to 0.933, with an average of 0.640. All the test strains were clustered into two groups at genetic similarity of 0.593. The strains 1-17 were grouped into IG-I, belonging to Fusarium solani and F. solani var. coeruleum, while the strains 18-21 were grouped into IG-II, belonging to F. ventricosum. All the 21 strains could be entirely distinguished at genetic similarity of 0. 933. The SSR loci in the Fusarium genomes were rich in polymorphism. The ISSR grouping had definite correlation with the species classification, but less correlation with the geographic origin of the strains. Within the same ISSR groups, there existed definite correlation between the genetic similarity and the geographic origin of the strains. Within the same species collected from the same regions and same host plants, there existed definite genetic difference among the strains of the same species.