Synaptic plasticity realized by selective oxidation of TiS3 nanosheet for neuromorphic devices.

Memristive devices operating analogous to biology synapses demonstrate great potential for neuromorphic applications. Here, we reported the space-confined vapor synthesis of ultrathin titanium trisulfide (TiS3) nanosheets, and subsequent laser manufacturing of a TiS3-TiOx-TiS3 in-plane heterojunction for memristor applications. Due to the flux-controlled migration and aggregation of oxygen vacancies, the two-terminal memristor demonstrates reliable "analog" switching behaviors, in which the channel conductance can be incrementally adjusted by tuning the duration and sequence of programming voltage. The device allows the emulation of basic synaptic functions, featuring excellent linearity and symmetry in conductance change during long-term potentiation/depression processes. The small asymmetric ratio of 0.15 enables it to be integrated into a neural network for the pattern recognition task with a high accuracy of 90%. The results demonstrate the great potential of TiS3-based synaptic devices for neuromorphic applications.

2D Indium Phosphorus Sulfide (In2 P3 S9 ): An Emerging van der Waals High-k Dielectrics.

2D van der Waals (vdW) semiconductors hold great potentials for more-than-Moore field-effect transistors (FETs), and the efficient utilization of their theoretical performance requires compatible high-k dielectrics to guarantee the high gate coupling efficiency. The deposition of traditional high-k dielectric oxide films on 2D materials usually generates interface concerns, thereby causing the carrier scattering and degeneration of device performance. Here, utilizing a space-confined epitaxy growth approach, the authors successfully obtained air-stable ultrathin indium phosphorus sulfide (In2 P3 S9 ) nanosheets, the thickness of which can be scaled down to monolayer limit (≈0.69 nm) due to its layered structure. 2D In2 P3 S9 exhibits excellent insulating properties, with a high dielectric constant (≈24) and large breakdown voltage (≈8.1 MV cm-1 ) at room temperature. Serving as gate insulator, ultrathin In2 P3 S9 nanosheet can be integrated into MoS2 FETs with high-quality dielectric/semiconductor interface, thus providing a competitive electrical performance of device with subthreshold swings (SS) down to 88 mV dec-1 and a high ON/OFF ratio of 105 . This study proves an important strategy to prepare 2D vdW high-k dielectrics, and greatly facilitates the ongoing research of 2D materials for functional electronics.

Correlation analysis of mandarin fish (Siniperca chuatsi) growth hormone gene polymorphisms and growth traits.

Screening of trait-associated molecular markers can be used to enhance the efficiency of selective breeding. Previously, we produced the first high-density genetic linkage map for the mandarin fish (Siniperca chuatsi) and identified 11 quantitative-trait loci significantly associated with growth, of which one is located within the growth hormone (GH) gene. To investigate the GH gene polymorphisms and their correlation with growth, the complete sequence was cloned and 32 single-nucleotide polymorphisms (SNPs) and one simple-sequence repeat (SSR) were identified. Of which, eight SNPs (G1-G8) and the SSR (GH-AG)were selected for genotyping and correlation analysis with growth traits in a random population. The results showed that the four novel polymorphicloci (G1, G2, G3 and GH-AG) were significantly correlated with growth traits of mandarin fish (P < 0.05). Of these, G1, G3 and GH-AG showed highly significant correlations with multiple growth traits (P < 0.01) and the combined SNP analysis showed that G1-G3 formed four effective diplotypes (D1-D4), among which D1 was highly significantly greater than D4 (P < 0.01) for some important growth traits. In conclusion, our results show that the four polymorphic loci G1-G3 and GH-AG within the mandarin fish GH gene are significantly correlated with growth traits and could be used as candidate molecular markers for selective breedingof superior varieties of mandarin fish.

[Studies on chemical constituents from seeds of Euryale ferox].

OBJECTIVE: To study the chemical constituents from the seeds of Euryale ferox. METHODS: The chemical constituents were isolated by silica gel column, Sephadex LH-20 and their structures were identified by physico-chemical and spectral analysis. RESULTS: Seven compounds were purified from the 95% ethanol extract. These constituents were elucidated as protocatechuic acid (1), gallic acid (2), gallic acid ethyl ester(3),5 ,7-dihydroxychromone(4), ß-sitosterol(5), daucosterol(6), and 5,7-dihydroxy-6,4'-dimethoxyflavone(7), respectively. CONCLUSION: All compounds are isolated from this plant for the first time.