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Nitric oxide (NO) releasing vascular graft is promising due to its merits of thromboembolism reduction and endothelialization promotion. In this study, keratin-based NO donor of S-nitrosated keratin (KSNO) was blended with poly(vinyl alcohol) (PVA) and further crosslinked with sodium trimetaphosphate (STMP) to afford PVA/KSNO biocomposite films. These films could release NO sustainably for up to 10 days, resulting in the promotion of HUVECs growth and the inhibition of HUASMCs growth. In addition, these films displayed good blood compatibility and antibacterial activity. Taken together, these films have potential applications in vascular grafts.

A biocompatible hydrogel is ideal for tissue engineering and regeneration. In this study, methacrylated keratin (KerMA) was synthesized for the first time and then blended with poly(ethylene glycol dimethacrylate) (PEGDMA) to form hydrogel through photocrosslinking. The chemical structure, gelation time, swelling behavior, hydrophilicity, cytotoxicity, and 3D printability of PEGDMA/KerMA hydrogels were characterized and exploited. The PEGDMA/KerMA hydrogels performed good cytocompatibility, providing potential applications for tissue engineering and regenerative medicine.

Copper-incorporating PCL/keratin grafts could generate NO catalytically, resulting in the accelerated growth of HUVECs and the inhibited proliferation of HUASMCs. These grafts could inhibit thrombus formation and retain patency for 3 months in vivo.

Valeriana jatamansi Jones is utilized for medicinal purposes in China, and is also an important substitute for European Valeriana officinalis. The major active principles are generally called valepotriates, which belong to iridoids compounds. To better understand the iridoid biosynthesis pathway in V. jatamansi, we generated transcriptome sequences from the leaf and root tissues, and performed de novo sequence assembly, a total of 183,524,060 transcripts and 61,876 unigenes for V. jatamansi were obtained from 13.28 Gb clean reads. 56,641 unigenes were annotated by public databases, while 5,235 unigenes remained unannotated. Different unigenes in V. jatamansi were identified by MISA analysis, and 5,195 unigenes containing Simple Sequence Repeat (SSR) were identified. When examining the annotation of transcriptome contigs against the KEGG database, we identified 24 unigenes that could be classified into 24 enzyme categories associated with three metabolic pathways leading to iridoid biosynthesis, 6 genes of MVA pathways, 9 genes of MEP pathways and 9 genes of iridoids pathways. We selected 9 genes encoding key enzymes in the iridoid pathway of V. jatamansi to examine their organ specificity of expression using quantitative real-time PCR (qPCR). In conclusion, we generated a comprehensive transcriptome assembly representing the gene space in V. jatamansi, and the genomic dataset and analyses presented here lay the foundation for further research on this important medicinal plant.

A D-π-A conjugated polydentate ligand chromophore, N-8'-quinolyl-2,4,6- trihydroxyl benzamide (NQTB), was identified and synthesized using tri-hydroxyl phenol as donated-electron group, N-heterocycle quinoline as accepted-electron one and CN bond as bridged one. It was expected to chelate some heavy metal ions with prominent colorimetric or spectral changes. After its UV-vis absorption spectrum was investigated in detail, it was noted that NQTB possessed excellent spectral recognition ability to Cu

A D-π-A conjugated polydentate ligand chromophore, N-8′-quinolyl-2,4,6- trihydroxyl benzamide (NQTB), was identified and synthesized using tri-hydroxyl phenol as donated-electron group, N-heterocycle quinoline as accepted-electron one and C N bond as bridged one. It was expected to chelate some heavy metal ions with prominent colorimetric or spectral changes. After its UV–vis absorption spectrum was investigated in detail, it was noted that NQTB possessed excellent spectral recognition ability to Cu2+ and Co2+ from other coexisting ions in aqueous. Under the optimized conditions, NQTB could simultaneously discriminate trace Cu2+ and Co2+ in environmental aqueous samples with low detection limits (1.9 × 10−8 mol/L and 5.7 × 10−8 mol/L) and satisfying analytical precisions (R.S.D. ≤3.3% and ≤2.6%) respectively. The sensing mechanism was confirmed to form some stable 5-membered-co-6-membered condensed rings between Cu2+/Co2+ and O/N atoms in NQTB.

Jammers characterized by their instantaneous frequencies can be effectively mitigated in direct sequence spread spectrum communications by using open-loop adaptive excision filters. The primary requirement for these filters is that they must possess a notch in tune with the jammer instantaneous frequency (IF) to annihilate the interference power at every time sample. The interference time-varying frequency can be obtained using existing IF estimators, including quadratic time-frequency distribution methods. Without focusing on any specific estimator, we develop expressions for the receiver performance using a general class of multiple-zero FIR excision filters and show the dependence of the bit error rate (BER) on the filter order and its group delay. The effect of inaccuracies in the jammer instantaneous frequency information on the receiver performance is considered and evaluated as a function of the filter notch bandwidth. The latter is defined by the filter zero multiplicity, which is shown to be an important factor in the analysis of the correlator signal-to-noise ratio (SNR).

We propose to apply blind source separation techniques for jammer mitigation in spread spectrum (SS) communication systems. These techniques strive to separate the jammer from the signal and as such produce a signal with reduced jammer contamination. With the jammer mostly mitigated through the separation process, the SS system requires smaller spreading gain and transmission bandwidth than the case if no separation is performed. The proposed spread spectrum receiver based on source separation improves the SNR at the correlator output and its performance is robust to multipath and coherent jamming environments. Simulation results including the bit error rates are provided to illustrate the effectiveness of the proposed approach.

Direct sequence spread spectrum (DSSS) systems are widely used in in a variety of applications including the suppression of a strong interfering signal due to jamming or multipath propagation. Time-frequency distributions (TFD) are applied for interference excision in spread spectrum communication systems. The focus is on jammers consisting of pulses of constant envelope frequency modulated interference. The time-support and the instantaneous frequency (IF) information provided by the TFD are used to reduce the jammer effect on the receiver performance. This is achieved by applying an excision notch filter with a null placed at the interference IF. The filter is turned on and off in synchronisation with the interference duty cycle. The bit error rates at different frequencies are given and compared with those obtained using multiresolution analysis.

A new technique for interference excision in PN spread spectrum communications using time-frequency distributions is introduced. The excision filter coefficients under this technique depend on the jammer power and its the instantaneous frequency information, both values are gained in the time-frequency domain. The dependency of the excision filter characteristics on the interference power, which was absent in previous contributions in this area, is of significant importance, as it allows optimum trade-off between interference removal and the amount of the filter self-noise generated from the induced correlation across the PN chip sequence. This trade-off is bounded by the two extreme cases of no self-noise, which implies preprocessing disabled, and full interference excision, which is the case previously considered. In this paper we derive the FIR excision filters that minimize the receiver signal-to-noise ratio for a simple jammer case.

The zero-tracking time-frequency distribution (TFD) is introduced. The local autocorrelation function of the TFD, defined by an appropriate kernel, is used to form a polynomial whose roots correspond to the instantaneous frequencies of the multicomponent signal. Two techniques for zero-tracking based on the TFD are presented. The first technique requires updating all of the polynomial signal and extraneous zeros, and is based on the formula relating to the first order approximation, the changes in the polynomial roots and coefficients. The second technique employs the zero-finding Newton's method to only obtain the zero-trajectories of interest.