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Carcinine is a natural imidazole-containing peptide derivative. It is widely used in the cosmetics industry as anti-aging supplement with antioxidant, anti-glycation and glycation reversal functions, and it also has a notable pharmacological effect as anti-tumor drug and in protection against retinopathy. However, a technological method for synthesis and production of carcinine has not been established. In this study, a whole-cell transformation system converting β-alanine and histamine to carcinine by the enzymes Ebony and phosphopantetheine transferase (Sfp) has been developed. The results revealed that the catalytic efficiency of the strain containing the fusion protein of Ebony and Sfp (Sfp-glycine-serine-glycine-Ebony, SGE) in Escherichia coli W3110 (WSGE strain) is significantly higher (7.45 mM) than the combinatorial strain of pET28a-ebony and pACYCDuet-sfp in E. coli BL21(DE3) (BSE strain) (2.17 mM). Under the optimal reaction conditions (25 ℃, pH 7.0, 12.5 g/L wet cells, 20 mM β-alanine and 40 mM histamine), the carcinine can be quickly synthesized within 24 h up to a concentration of 22.63 mM. To achieve a continuous and efficient conversion of the precursors, a batch-feeding catalysis was designed. With this system, β-alanine (40 mM) and histamine (40 mM) could be completely transformed to carcinine (40.34 mM) in 36 h with a productivity of 0.204 g/L h reaching a titer of 7.34 g/L. Hence, the batch-feeding whole-cell biocatalysis is a promising technology for the high yield production of carcinine which can promote the industrial production of carcinine.

At present, the load diagram of pumping wells mostly uses load sensors to obtain load data. However, the load sensor is prone to mechanical fatigue during the measurement process, which results in measurement data drift distortion and large errors. This paper presents an electrical parameter measurement method to improve this problem. The electrical indicator diagram is obtained by measuring the instantaneous input power of the driving motor of the pumping unit, calculating the transmission loss in real time, and establishing the mathematical model of the polished rod load and displacement of the pumping unit. The correctness and effectiveness of the electrical indicator diagram were verified by field experiments.

The abscisic acid (ABA) receptor PYR/PYL/RCAR, located upstream of the ABA signaling pathway, recognizes ABA signals and initiates the primary process of signal transduction. In our previous study, we found that the PYL4 gene in tomato plants was significantly upregulated after exogenous treatment with the hormone ABA. The present study used virus-induced gene silencing (VIGS) to further elucidate the role of the PYL4 gene in response to drought in tomato (Solanum lycopersicum) plants. Under the drought treatment, the SlPYL4-silenced plants wilted faster than the control plants did. Physiological indicators showed that the total reactive oxygen species (ROS) content and superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities of the SlPYL4-silenced plants were lower than those of the control plants after 3 and 6 h of drought stress treatment. After 3 h of drought treatment, hydrogen peroxide (H2O2) and superoxide anion (O2−.) accumulated much more in the leaves of the SlPYL4-silenced plants than in the leaves of the control plants. These results indicated that PYL4 plays a positive role in drought tolerance in tomato plants. Our results also suggest that SlPYL4 is located upstream of the ABA pathway to regulate the expression of PP2C, SnRK, and AREB/ABF genes.

Deep reinforcement learning (DRL) integrates the advantages of the perception of deep learning and enables reinforcement learning scale to problems with high dimensional state and action spaces that were previously intractable. The success of DRL primarily relies on the high level representation ability of deep learning. To obtain a good performed representation model, excessive training samples and training time are necessary. However, collecting a large number of samples in real world is extremely expensive and time consuming. To mitigate the sample inefficiency problem, we propose a novel model-based reinforcement learning method by combining conditional generative adversarial networks (CGAN-MbRL) with the state-of-the-art policy learning method. The proposed CGAN-MbRL can directly deal with the high dimensional state, and mitigate the problem of sample inefficiency to some extent. Finally, the effectiveness of the proposed method is demonstrated through the illustrative data and the RL benchmark.

Conversion of levulinic acid and its esters into versatile γ-valerolactone (GVL) is a pivotal and challenging step in biorefineries, limited by high catalyst cost, the use of hydrogen atmosphere, or tedious catalyst preparation and recycling process. Here we have successfully synthesized a ternary magnetic nanoparticle catalyst (Al2O3-ZrO2/Fe3O4(5)), over which biomass-derived methyl levulinate (ML) can be quantitively converted to GVL with an extremely high selectivity of > 99% and yield of ~98% in the absence of molecular hydrogen. Al2O3-ZrO2/Fe3O4(5) incorporates simultaneously inexpensive alumina and zirconia onto magnetite support by a facile coprecipitation method, giving rise to a core-shell structure, well-distributed acid-base sites, and strong magnetism, as evidenced by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-angle annular dark-field scanning-TEM (HAADF-STEM), SEM-energy dispersive X-ray spectroscopy (SEM-EDX), temperature-programmed desorption of ammonia (NH3-TPD), temperature-programmed desorption of carbon dioxide (CO2-TPD), pyridine-adsorption infrared spectra (Py-IR), and vibrating sample magnetometry (VSM). Such characteristics enable it to be highly active and easily recycled by a magnet for at least five cycles with a slight loss of its catalytic activity, avoiding a time-consuming and energy-intensive reactivation process. It is found that there was a synergistic effect among the metal oxides, and the high efficiency and selectivity originating from such synergism are evidenced by kinetic studies. Furthermore, a reaction mechanism regarding the hydrogenation of ML to GVL is proposed by these findings, coupled with gas chromatography-mass spectrometry (GC-MS) analysis. Accordingly, this readily synthesized and recovered magnetic nanocatalyst for conversion of biomass-derived ML into GVL can provide an eco-friendly and safe way for biomass valorization.

Aerobic granule is a special microbial aggregate associated with biofilm structure. The formation of aerobic granular sludge is primarily depending on its bacterial community and relevant microbiological properties. In this experiment, a strain with high microbial attachment was isolated from aerobic granular sludge, and the detailed characteristics were examined. Its high attachment ability could reach 2.34 (OD600nm), while other low attachment values were only around 0.06-0.32, which indicated a big variation among the different bacteria. The strain exhibited a very special morphology with many fibric fingers under SEM observation. A distinctive behaviour was to form a spherical particle by themselves, which would be very beneficial for the formation and development of granular sludge. The EPS measurement showed that its PN content was higher than low attachment bacteria, and 3D-EEM confirmed that there were some different components. Based on the 16S rRNA analysis, it was identified to mostly belong to Stenotrophomonas. Its augmentation to particle sludge cultivation demonstrated that the strain could significantly promote the formation of aerobic granule. Conclusively, it was strongly suggested that it might be used as a good and potential model strain or chassis organism for the aerobic granular sludge formation and development.

In this paper, an improved cross coupled map lattice (CCML) which is derived from CCML is proposed. The experimental analysis of CCML shows that it exhibits weak or even lose chaotic behaviors in a large range of parameters. To enhance its chaotic performance, the new model changes the internal chaotic map of CCML from the logistics map to the tent map and introduces the module operations to limit the obtained value. The theoretical analysis and experimental results prove that the proposed model has a broad chaotic regime over an extensive range of system parameters, positive Lyapunov exponents, higher information entropies and lower mutual information values when compared to CCML, which are highly suitable for chaos-based image encryption. Moreover, this paper applies that model on a bit-level image encryption scheme. The algorithm consists of three main operations: the generation of secret keys, confusion and diffusion operations that can break the limitation of row and column. To confirm the novel algorithm's effectiveness and safety against the common types of attacks, many experiments are done and security analyses are discussed. It demonstrates the good chaos of the proposed model from the aspect of encryption performance.

Flexible dielectric materials with ultrahigh energy density (Ue) is of critical importance to reduce the size of dielectric capacitors, which has recently drawn ever-increasing attention. Herein, different from the incorporation of traditional 1D/2D inorganic nanofiller into single/multi-layer polymer matrix, a multifunctional poly (p-phenylene terephthalamide) (PPTA)-based derivative fluxible polymer (f-PPTA) nanocluster is selected and introduced to typical ferroelectric poly (vinylidene fluoride) (PVDF) matrix. As a novel polymer-based nanofiller, the f-PPTA nanocluster consists of self-bundled parallel sulfonated PPTA skeleton and grafted with octadecylamine polyoxyethylene ether amphiphilic (PEGO) amine ligand through ionic interaction. In the multi-arm amphiphilic PEGO, one alkyl chain with the length of 15 carbon atoms provides similar hydrophobic nature to that of PVDF, which contributes to improving the interfacial compatibility between polymer nanocluster and matrix. Furthermore, the relatively short hydrophilic chain with the length of 8 carbon atoms induces a specific necklace-like arrangement of the f-PPTA nanoclusters in PVDF matrix during film fabrication spontaneously. Consequently, an ultrahigh Ue ~ 22.5 J•cm−3 of the dielectric film is acquired at 600 MV•m−1 electric field. This value is the highest reported so far among all the poly (vinylidene fluoride) (PVDF)-based dielectric nanocomposites to the best of our knowledge. In addition, the elongation at break of the film can be increased to 390%, which is over 9 times that of pure PVDF sample. This work provides a new route to PVDF-based polymer nanocomposites with ultrahigh Ue and highly stretchable performance.

Background Atrial fibrillation (AF), the most common sustained arrhythmia, significantly increases cardiovascular and cerebrovascular morbidity and mortality. The pathogenesis and treatment of AF remain a major challenge in the field of cardiology. We previously found that cold-inducible RNA-binding protein (CIRP) regulated ventricular repolarization by posttranscriptionally regulating Kv4.2/4.3 ion channels in rats, but the role of CIRP in AF is not clear. Objective The purpose of this study was to confirm that CIRP participates in atrial electrophysiological remodeling and AF occurrence by regulating atrial channels posttranscriptionally. Methods Programmed intra-atrial stimulation was used to induce AF in wild-type or transcription activator-like effector nucleases–based CIRP knockout (KO) rats. Atrial optical mapping, patch clamp, Western blotting, RNA immunoprecipitation, and luciferase reporter assays were performed to evaluate the underlying mechanism of atrial electrical remodeling. Results First, we observed a shortened atrial effective refractory period and increased susceptibility to AF in CIRP KO rats. Second, atria-specific CIRP delivery through an adeno-associated viral vector serotype 9 prolonged the atrial effective refractory period and attenuated AF development in CIRP KO rats. Third, we observed the shortened action potential duration and enhanced expression of Kv1.5 and Kv4.2/4.3 in KO rats. The transient outward current blocker 4-Aminopyridine and ultrarapid component of the delayed rectifier current blocker Diphenyl phosphine oxide-1 restored the shortened action potential duration in KO atria. Finally, we demonstrated that CIRP suppressed Kv1.5 and Kv4.2/4.3 expression by directly targeting their 3′-untranslated regions. Conclusion CIRP plays a protective role in preventing AF onset through the posttranscriptional regulation of Kv1.5 and Kv4.2/4.3.

In this study, we explored the viral diversity and community structures of the ticks collected from dogs and detected possible tick-borne viruses (TBVs) using metagenomic analysis. Additionally, full-length sequences and the structural, phylogenetic and molecular features of the possible TBVs were characterized using bioinformatics tools. The sequence run produced 12,254,268 reads and 6,667,259 unique reads from the tick pools. Further analysis of the viral reads revealed that 92.73% were similar to ssRNA viruses, and 90.5% of the total viral sequences belonged to Non-classified viral families. Of the 29 classified viral families, most virome sequences were homologous with vertebrate viruses from Circoviridae, plant viruses from Virgaviridae, phages from Microviridae, insect viruses from Baculoviridae, and giant viruses from Mimiviridae. In the process of assembly of reads, large contigs representing four virus families were identified, including Phenuiviridae, Chuviridae, Parvoviridae and Non-classified families. Some sequences of Non-classified family shared a highly divergent amino acid sequence identities from existing virus sequences. The importance of these newly identified virus contigs to public and veterinary health needs additional researches. Because of the lack of the acquired viral reads from these families, we only demonstrated the complete sequences of Circoviridae in detail. The complete canine circovirus (CaCV)-NC21 genome detected from police dogs was 2,063 bp long with a GC content of 53.6%. Our results suggested that tick viromes collected from dogs contained diverse sequences with a broad range of animal, insect, plant, and phage viruses, which may reflect the ecological characteristics of the dogs and their ticks. Furthermore, our study revealed the existence of the partial contigs belonging to the four virus families in ticks. More researches are needed to verify their importance to public and veterinary health. As well, our detection of CaCv-NC21 demonstrated that ticks can harbor and potentially transmit canine circoviruses.

Oxidative stress-induced DNA damage, the senescence-associated secretory phenotype (SASP), and impaired autophagy all are general features of senescent cells. However, the cross-talk among these events and processes is not fully understood. Here, using NIH3T3 cells exposed to hydrogen peroxide stress, we show that stress-induced DNA damage provokes the SASP largely via cytosolic chromatin fragment (CCF) formation, which activates a cascade comprising cGMP-AMP synthase (cGAS), stimulator of interferon genes protein (STING), NF-κB, and SASP, and that autolysosomal function inhibits this cascade. We found that CCFs accumulate in senescent cells with activated cGAS-STING-NF-κB signaling, promoting SASP and cellular senescence. We also present evidence that the persistent accumulation of CCFs in prematurely senescent cells is partially associated with a defect in DNA-degrading activity in autolysosomes and reduced abundance of activated DNase 2α. Intriguingly, we found that metformin- or rapamycin-induced activation of autophagy significantly lessened the size and levels of CCFs and repressed the activation of the cGAS-STING-NF-κB-SASP cascade and cellular senescence. These effects of autophagy activators indicated that autolysosomal function contributes to CCF clearance and SASP suppression, further supported by the fact that the lysosome inhibitor bafilomycin A1 blocked the role of autophagy-mediated CCF clearance and senescence repression.

Ticks are involved in the transmission of various arboviruses and some tick-borne viruses pose significant threats to the health of humans or livestock. This study aimed to investigate the geographical distribution of tick species and tick-associated viruses in central and eastern China. Total 573 ticks from domestic animals including dogs, sheep and cattle were collected in 2017. Two genera of ticks were identified including Rhipicephalus and Haemaphysalis. Sequencing was performed on Miseq Illumina platform to characterize the tick viromes from the four different sampling locations. Following trimming, 13,640 reads were obtained and annotated to 19 virus families. From these sequences, above 37.74% of the viral reads were related to the RNA viruses. Virome comparison study revealed that the tick viral diversity was considerably different in the two identified tick genera. The viral diversity of R. microplus was significantly different from that of other Rhipicephalus species. On the other hand, substantial overlap in viral species was observed between the same genera. In addition, we found no evidence that the natural host played a major role in shaping virus diversity based on the comparison of their viromes. Rather, the geographic location seems to significantly influence the viral families. Phylogenetic study indicated that the novel negative-sense RNA viruses identified in this study was closely related to Bole tick virus 1 and 3 viruses. In conclusion, the present study provides a baseline for comparing viruses detected in ticks, according to species, natural hosts, and geographic locations.

Topological insulator/perovskite manganese oxide composites (Bi2Se3/La0.7Sr0.3MnO3) were prepared using the bonded-exfoliated method and the transport properties were studied. The resistivity of the bonded manganese oxide substrate was 6 orders of magnitude larger than that of a Bi2Se3 single crystal, implying that the bonded manganese oxide acted as an insulator substrate. The intrinsic resistance peak of the manganese oxide was present in the temperature-dependent resistivity curve. Metal-insulator transition induced by the magnetic field at a low temperature was observed. The simple parallel model cannot account for the electrical properties, as the conducting manganese oxide grains were bonded by polymeric silicone rubber and resistivity peaks were present only when the thickness of the Bi2Se3 layer was less than 1.043 μm. The spin injection may be present in the composite structure.

BackgroundSufficient crop yield while maintaining soil health and sustainable agricultural development is a global objective, serving a special challenge to certain climate-sensitive plateau areas. Despite conducting trails on a variety of soil amendments in plateau areas, systematic research is lacking regarding the influences of organic and inorganic amendments on soil quality, particularly soil microbiome. To our knowledge, this was the first study that compared the effects of inorganic, organic, and mixed amendments on typical plateau crop hulless barley (Hordeum vulgare L. var. nudum; also known as “Qingke” in Chinese) in Tibet over the course of tillering, jointing, and ripening. ResultsMicrobial communities and their responses to amendments, soil properties, Tibetan hulless barley growth, yield, and their indicator microbial species were investigated. Results indicated that mixed organic and inorganic amendments promoted the abundance of rhizosphere microorganisms, enhancing the rhizosphere root-microbes interactions and resistance to pathogenic bacteria and environmental stresses. Additionally, values of total organic carbon (TOC) and carbon to nitrogen (C/N) ratio and the hullesss barley yield were the highest when mixed organic and inorganic amendments were applied. The rhizosphere microbiome demonstrated its unique adaptation to the plateau environment in carbon, nitrogen, sulfur, and phosphorus cycles, as well as resistance to environmental stresses. The 23 genes involved in plant growth and environmental adaptation in the mixed amendments treatments were significantly higher than other treatments. ConclusionsFindings from this study suggest that the mixed organic/inorganic amendments can help establish a healthy microbiome and increase soil quality while achieving sufficient hulless barley yields in Tibet and presumably other similar geographic areas of high altitude.