A triple-shape memory polyurethane (TSMPU) with poly(ε-caprolactone) -diols (PCL-diols) as the soft segments and diphenyl methane diisocyanate (MDI), N,N-bis (2-hydroxyethyl) cinnamamide (BHECA) as the hard segments was synthesized via simple photo-crosslinking of cinnamon groups irradiated under λ > 280 nm ultraviolet (UV) light. Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance ( 1 H-NMR) and ultraviolet-visible absorption spectrum (UV−vis) confirmed the chemical structure of the material. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) results demonstrated that the photocrosslinked polymer possessed two transition temperatures, one is due to the melting point of the soft segment PCL-diols, and the other is due to the glass transition temperature. All these contributed to the cross-linked structure of the hard segments and resulted in an excellent triple-shape memory effect. Alamar blue assay showed that the material has good non-cytotoxicity and can be potentially used in biomaterial devices.

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In this study, we synthesized one type of star-shaped polyurethane (SPU) with star-shaped poly(ε-caprolactone) (SPCL) containing different arm numbers as soft segment and 4,4'-diphenyl methane diisocyanate (MDI) as well as chain extender 1,4-butylene glycol (BDO) as hard segment. Proton nuclear magnetic resonance (1H-NMR) confirmed the chemical structure of the material. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) results indicated that both the melting temperature (Tm) and transition temperature (Ttrans) of SPU decreased with the hard segment composition increase. X-ray diffraction (XRD) results demonstrated that the increase of the crystallinity of SPU following the raised arm numbers endowed a high shape fixity of six-arm star-shaped polyurethane (6S-PU) and a wide melting temperature range, which resulted in an excellent triple-shape memory effect of 6S-PU. The in vitro cytotoxicity assay evaluated with osteoblasts through Alamar blue assay demonstrates that this copolymer possessed good cytocompatibility. This material can be potentially used as a new smart material in the field of biomaterials.

In this study, we synthesized one type of biocompatible and biodegradable cross-linked star poly(ε-caprolactone)–poly(ethylene glycol) (c-4sPCL–PEG) with an excellent temperature memory effect (TME) by photo-cross-linking of cinnamon group terminated four arms poly(ε-caprolactone) (4sPCL–CA) and cinnamon group terminated poly(ethylene glycol) (PEG–CA) through the irradiation of 365 nm ultraviolet (UV) light. The results of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) demonstrated that the c-4sPCL–PEG networks possessed a broad transition temperature region from 20 to 55 °C, which including a wide high elasticity transition region and a melting transition region. A remembered temperature in this temperature range, which is close to body temperature, could be gained by adjusting the deformed temperature (T d). Moreover, the TME could be tuned by simply changing the molecular weight or the content of PCL segment. The mechanism of the TME was investigated in detail for the first time with X-ray diffractometry (XRD) and two-dimensional infrared correlation spectroscopy (2D-FTIR) at different temperatures, and the results indicated that the TME was resulted from a change in partial crystallization of the star cross-linked polymer networks, which led to the wide transition temperature. The study provides a facile strategy toward the design and engineering of a promising smart material for applications in the field of smart biomedical devices.

We propose a high-efficiency molecular junction consisting of a double-coupled-quantum-dot molecule sandwiched between two metallic electrodes. ZT can be enhanced in the Fano-line-shape regime, and it is sensitive to the magnetic flux threading through the double-coupled-quantum-dot molecular junction. This is mainly due to the local density of states in the Fano-line-shape regime may become narrower, and an abrupt changing in the conductance (transmission) spectrum is developed. We find the value of ZT can exceed 1 at room temperature by controlling the chemical potential or magnetic flux. So our results indicate such a molecular junction may be used to the solid-state thermoelectric energy-conversion device at room temperature.

Two-dimensional MA2Z4, as another system of a two-dimensional material family, can obtain different materials and considerable properties by replacing the elements M, A, and Z. At present, the physical properties and optical response of MA2Z4 materials have been studied, but there is still a lack of research on the application of MA2Z4 as a transistor channel material to investigate its transistor performance. Here, we employ WGe2N4 as a representative to systematically study the bounce-to-transport properties and gate control capability of ML WGe2N4 field effect transistors below 10 nm via ab initio quantum transport calculations. Until the channel length is down to 3.0 nm, the optimized n/p-type doped WGe2N4 metal–oxide–semiconductor field-effect transistors with proper concentrations and underlap structures can satisfy the high-performance requirements of International Technology Roadmap for Semiconductors of 2013 version, by considering the on-current, subthreshold swing, intrinsic delay time, and dynamic power indicator. Therefore, we can estimate that the monolayer WGe2N4 is a competitive alternative for transistor channel materials in the post-silicon era.

Enhanced spin figure of merit in a Rashba quantum dot ring connected to ferromagnetic leadsWe propose a pure thermoelectric spin generator based on a Rashba quantum dot molecular junction by using the temperature difference instead of the usual voltage bias difference. A magnetic flux penetrating through the device is also considered. The spin Seebeck coefficient S S and the spin figure of merit Z S T of the molecular junction are calculated in terms of the Green's function formalism and the equation of motion (EOM) technique. It is found that a pure spin-up (spin-down) Seebeck coefficient can be generated by the coaction of the magnetic flux and the Rashba spin-orbit (RSO) interaction.

Bioinformatic tools and databases for glycobiology and glycomics research are playing increasingly important roles in functional studies. However, to verify hypotheses generated by computational glycomics with empirical functional assays is only an emerging field. In this study, we predicted glycan epitopes expressed by a cancer-derived mucin, MUC1, by computational glycomics. MUC1 is expressed by tumor cells with a deficiency in glycosylation. Although numerous diagnostic reagents and cancer vaccines have been designed based on abnormally glycosylated MUC1 sequences, the glycan and peptide sequences responsible for immune responses in vivo are poorly understood. The immunogenicity of synthetic MUC1 glycopeptides bearing Tn or sialyl-Tn antigens have been studied in mouse models, while authentic glyco-epitopes expressed by tumor cells remain unclear. To examine the immunogenicity of authentic cancer derived MUC1 glyco-epitopes, we expressed membrane bound forms of MUC1 tandem repeats in Jurkat, a mutant cancer cell line deficient of mucin-type core-1 β1–3 galactosyltransferase activity, and immunized mice with cancer cells expressing authentic MUC1 glyco-epitopes. Antibody responses to individual glyco-epitopes were determined by chemically synthesized candidate MUC1 glycopeptides predicted through computational glycomics. Monoclonal antibodies can be generated toward chemically synthesized glycopeptide sequences. With RPAPGS(Tn)TAPPAHG as an example, a monoclonal antibody 16A, showed 25-fold higher binding to glycosylated peptide (EC50=9.278±1.059 ng/ml) compared to its non-glycosylated form (EC50=247.3±16.29 ng/ml) as measured by ELISA experiments with plate-bound peptides. A library of monoclonal antibodies toward authentic MUC1 glycopeptide epitopes may be a valuable tool for studying glycan and peptide sequences in cancer, as well as reagents for diagnosis and therapy.