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The genus Streptomyces comprises the most important chitin decomposers in soil and revealing their chitinolytic machinery is beneficial for the conversion of chitinous wastes. Streptomyces sp. SCUT-3, a chitin-hydrolyzing and a robust feather-degrading bacterium, was isolated previously. The potential chitin-degrading enzymes produced by SCUT-3 were analyzed in the present study. Among these enzymes, three chitinases were successfully expressed in Pichia pastoris at comparatively high yields of 4.8 U/mL (SsExoChi18A), 11.2 U/mL (SsExoChi18B), and 17.8 U/mL (SsEndoChi19). Conserved motifs and constructive 3D structures of these three exo- and endochitinases were also analyzed. These chitinases hydrolyzed colloidal chitin to chitin oligomers. SsExoChi18A showed apparent synergic effects with SsEndoChi19 in colloidal chitin and shrimp shell hydrolysis, with an improvement of 29.3 % and 124.9 %, respectively. Compared with SsExoChi18B and SsEndoChi19, SsExoChi18A exhibited the strongest antifungal effects against four plant pathogens by inhibiting mycelial growth and spore germination. This study provided good candidates for chitinous waste-processing enzymes and antifungal biocontrol agents. These synergic chitin-degrading enzymes of SCUT-3 are good targets for its further genetical modification to construct super chitinous waste-degrading bacteria with strong abilities to hydrolyze both protein and chitin, thereby providing a direction for the future path of the chitinous waste recycling industry.

Stimuli-responsive actuators (SRAs) that can harvest environmental energies and convert them to mechanical works without additional energy-supplying systems have revealed great potential for robotic applications. However, at present, the practical usage of SRAs is significantly limited due to the problems with respect to solo responsiveness, simple deformation, and the difficulties for large-scale and cost-effective production. In this paper, multi-responsive paper actuators with multicoating nanoarchitectonics that enable complex deformation have been fabricated through a very simple painting process on common papers. The resultant paper actuator permits large-scale and low-cost production (A4 size: ∼0.5 dollar). The paper actuators that consist of a paper/graphite/polydimethylsiloxane sandwich structure can be actuated by multi-form stimuli, including moisture, temperature, light, and volatile organic compounds. More importantly, the bending deformation of the paper actuators can be further programmed by controlling the pencil drawing orientation, providing the feasibility of performing more complex deformations. Several multi-responsive paper actuators, including organic compound-responsive smart devices working in the liquid environment, moisture-enabled terrestrial crawling actuator, and a light-responsive attitude-control actuator integrated with an airplane model, have been demonstrated. The development of multi-responsive yet cost-effective paper actuators may hold great promise for a wide range of practical applications, for instance, soft micro-electromechanical systems, lab-on-a-chip systems, smart homes, and robotics.

Monolithic Nd: YAG lasers pumped by laser diodes have been widely used in precision measurement fields due to its low frequency noise and intensity noise. Previously, people found that the intensity noise of the pump laser would affect the frequency noise of the Nd: YAG lasers, but the cause has not been well explained so far. In this paper, we propose that this effect is thermally induced. The experimental results agreed well with the theoretical model predictions in up to 60 kHz frequency range. The finding can provide ideas for further reducing the frequency noise of Nd: YAG lasers. We get about 300 Hz linewidth in NPRO laser pumped by single laser diode.

Surface-enhanced Raman spectroscopy (SERS) is an optical technique for molecule identification. However, fabrication of flexible and structured SERS substrates for performance improvement in a facile and cost-effective manner is challenging. In this work, we reported a polytetrafluoroethylene (PTFE)-based flexible SERS substrate by femtosecond laser direct writing (FsLDW) technology. The femtosecond laser-treated PTFE surface is 3D hierarchical micro-/nano-structures, and the structured PTFE-based SERS chip shows excellent performance enhancement. As a result, 10−7 M can be detected, which shows excellent potentials in developing flexible SERS for wearable electronics.

Ag2WO4 is a typically noble metal based photocatalyst with highly efficient photocatalytic activity. However, due to photocorrosion, the pristine Ag2WO4 is prone to inactivation during illumination. Constructing composite photocatalyst may be a useful method to promote the stability of Ag2WO4. In this work, Ag2WO4/graphitic carbon nitride nanotubes (g-C3N4 NTs) composite photocatalyst was prepared by adopting an in-situ composite strategy. The photocatalytic performance of the samples was discussed by the degradation of rhodamine B under visible light, and the catalytic mechanism was also analyzed. The characterization results show that the photocatalytic efficiency of the as-prepared Ag2WO4/g-C3N4 NTs composite increases firstly and then decreases along with the increase of the Ag2WO4 content. When the theoretical molar ratio of Ag2WO4:g-C3N4 NTs reaches 3:2, the photocatalytic degradation efficiency achieves the optimal value, that is 92.4% within 20 min, which obviously exceeds 2.8% of pure Ag2WO4 and 48.9% of pure g-C3N4 NTs. Moreover, the separation and migration efficiency of photoelectron–hole pairs of the composites can be accelerated in comparison with pure samples. In addition, superoxide radicals and hydroxyl radicals play major roles in the photocatalytic degradation process.

The AgBrO3/few-layer g-C3N4 composite photocatalyst has been developed via an in-situ synthetic method. The structure, morphology, light response range, separation and migration efficiency of the photogenerated electron–hole pairs and element valence state of the as-obtained samples have been characterized. The tetracycline was used to discuss the photocatalytic activities of the samples. The photocatalytic degradation mechanism of the as-obtained composites was also researched. The analysis results show that the photocatalytic degradation property of the asobtained composite photocatalyst appears to the tendency of first increasing and then decreasing with increasing the amount of AgBrO3 under visible light illumination. When the mass ratio of AgBrO3 to g-C3N4 is 4:3, in 60 min, the photocatalytic degradation efficiency of the as-obtained composites reaches the maximum of 79%. It is 37% and 45% higher than that of pure AgBrO3 and g-C3N4, respectively. Moreover, the separation and migration efficiency of the photogenerated electron–hole pairs of the as-prepared composites are also enhanced. In addition, superoxide radicals and holes are the dominant active species during the photocatalytic degradation process.

Hypothesis The transition metal phosphide is one of the promising bifunctional electrocatalysts for overall water splitting. Moreover, the activity of phosphide catalysts can be further enhanced by the cationic vacancy engineering. Experiments The self-growth Ni2P nanosheet arrays with abundant cationic vacancy defects (V-Ni2P/NF) has been synthesized via a facile multi-step reaction process involving hydrothermal, phosphorization and acid-etching of Mn which was doped in Ni2P nanosheets as a sacrificial dopant. Furthermore, the experimental studies and density functional theory (DFT) calculations were carried out to evaluate its electrochemical performance. Findings The chemical and electrocatalytic property of Ni2P were successfully optimized by cationic vacancy engineering and the obtained V-Ni2P/NF catalyst exhibited superior bifunctional catalytic performance for both hydrogen evolution (HER) and oxygen evolution reaction (OER) compared to pristine Ni2P and Mn-doped Ni2P in alkaline electrolyte. The V-Ni2P/NF can afford the current density of 10 mA cm−2 at a small overpotential of 55 mV for HER and 250 mV for OER. Additionally, the water electrolysis device assembled by the V-Ni2P/NF electrode as both the anode and cathode just requires a small voltage of 1.59 V to achieve 10 mA cm−2 and shows no obvious attenuation for 50 h.

To verify the feasibility and mechanical properties of assembled composite walls, three assembled composite walls were designed. Two bolted connection specimens in horizontal joints were tested under low-cycle reversed loading and monotonic loading, respectively. Then, the failure mechanism, hysteretic behaviour, ductility, energy dissipation capacity, slip and stress distribution of the connectors were studied. A specimen with grouting sleeve connection was tested under low-cycle reversed loading as a contrast specimen. In addition, a specimen with bolted connection under monotonic loading was simulated by the finite element method to study the effects on structural performance of the connectors and walls. The results show that the bolted connection is feasible, and compared with the grouting sleeve connection, the bearing capacity of the bolted connection specimen decreases by 17%, the displacement ductility coefficient increases by 52% and the cumulative energy consumption increases by 62%. Slippage between the connectors and the wallboard occurs mainly between the yield point and the peak point of the specimens. With the increase in plate thickness, the bearing capacity and initial stiffness increased, but there was no obvious effect on the appearance of the slip section. The larger the bolt diameter, the later the slip section forms. However, the bolt diameter does not have an obvious effect on the bearing capacity of the specimens.

The CdS/ spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method. The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids. The photocatalytic degradation mechanism of the as-developed heterojunction photocatalyst was also analyzed. Research results show that CdS nanoparticles are well dispersed in the surface layer of spherical g-C3N4. Moreover, the mass ratio of CdS to spherical g-C3N4 will influence the photocatalytic activity of the asdeveloped composites, which shows the trend of first increasing and then decreasing as it increased. When the mass ratio is 7:1, in 25 min, the as-developed heterojunction shows 93.2 % of the maximum photocatalytic efficiency and still exhibits 83.6 % after 5 times cycle testing. Moreover, the as-developed hybrids can accelerate the electron transport and improve the separation efficiency of photo-generated carriers compared with pure samples. In addition, the holes and superoxide radicals are dominating active species during the photocatalytic degradation process.

As the oldest venomous animals, centipedes use their venom as a weapon to attack prey and for protection. Centipede venom, which contains many bioactive and pharmacologically active compounds, has been used for centuries in Chinese medicine, as shown by ancient records. Based on comparative analysis, we revealed the diversity of and differences in centipede toxin-like molecules between Scolopendra mojiangica, a substitute pharmaceutical material used in China, and S. subspinipes mutilans. More than 6 000 peptides isolated from the venom were identified by electrospray ionization-tandem mass spectrometry (ESI-MS/MS) and inferred from the transcriptome. As a result, in the proteome of S. mojiangica, 246 unique proteins were identified: one in five were toxin-like proteins or putative toxins with unknown function, accounting for a lower percentage of total proteins than that in S. mutilans. Transcriptome mining identified approximately 10 times more toxin-like proteins, which can characterize the precursor structures of mature toxin-like peptides. However, the constitution and quantity of the toxin transcripts in these two centipedes were similar. In toxicity assays, the crude venom showed strong insecticidal and hemolytic activity. These findings highlight the extensive diversity of toxin-like proteins in S. mojiangica and provide a new foundation for the medical-pharmaceutical use of centipede toxin-like proteins.

Focused ion beam (FIB) machining has been demonstrated to be capable of fabricating nano- and micro-scale structures. In this paper we demonstrate techniques to design and fabricate 45° micro-mirrors into the end of multi-core fibres using FIB processing. The mirrors are fabricated by a two-step process: a scanning process which is used to make a rough cut followed by a polishing process to create an optical surface finish mirror. The machined 45° mirrors can be accurately aligned with optical fibre cores, which avoids issues associated with the alignment of external turning mirror components. Proof-of-concept demonstration shows that the fabricated structure is capable of measuring two-axis acceleration interferometrically with a linear response from 0.2 to 4 g and an rms. error of 0.03 g. Acceleration measurements of frequency response up to 700 Hz and cross-sensitivity of ∼4.3% are demonstrated.

SnO2/AgIO4 hybrids were fabricated by an in-situ synthetic method at room temperature. The structure, morphology, light response range, separation efficiency of the electron-hole pairs and elements of the as-synthesized samples were characterized by adopting X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectroscopy, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy, respectively. The synergistically photocatalytic degradation mechanism of the as-synthesized composites was also proposed. The experimental results reveal that under the visible light irradiation the as-synthesized SnO2/AgIO4 hybrids can enhance the photocatalytic degradation efficiency of rhodamine B compared to pure samples. With increasing the molar ratios of AgIO4 to SnO2, it displays the trend of first increasing and then decreasing. When it is 1:2 in 150 min, the as-prepared hybrids have the highest degradation efficiency of 93.1%, which increases by 6550.0%, 30.5%, and 1505.0% compared to those of pure SnO2, AgIO4, and TiO2 (P25), respectively. Moreover, the Sn-O-Ag cross-linking bonds are formed at the interfaces of SnO2 and AgIO4. In addition, superoxide anion radicals and holes play a major role in the process of photodegradation.

Background: Giant pituitary adenoma (GPA) (diameter >40 mm) remains challenging to treat, and the radical resection rate is low. The intraoperative multimodal navigation is sometimes used in endoscopic endonasal surgery (EES). However, the effect of this technique on GPA surgical outcomes is not clear. This study aims to explore the surgical and clinical outcomes of the navigation used in EES for GPA. Methods: A retrospective review of 60 consecutive patients with GPA who underwent EES was performed. The total resection rate, residual volume, clinical outcomes, and complications were compared. Factors associated with tumor gross total resection (GTR) were analyzed by multinomial logistic regression analysis. Results: There were 31 patients in the standard group in which intraoperative multimodal navigation was not used, with a mean maximum tumor diameter of 5.21±1.24 cm; meanwhile, there were 29 patients in the navigation group, in which navigation was used, with a mean maximum tumor diameter of 5.32±1.18 cm. GTR was achieved in 10 patients (32.26%) in the standard group, which was significantly lower than that in the navigation group (18/29=62.07%). The residual volume was 7.93±10.78 cm 3 in the standard group which was significantly greater than that in the navigation group (2.44±1.26 cm 3 , P=0.046). There was no significant difference between the two groups in terms of cerebrospinal fluid (CSF) leak, new pituitary deficit, and postoperative diabetes insipidus (DI). The higher Knosp grade of tumor, lobulated configuration and lack of intraoperative multimodal navigation use were relative risk factors associated with the GTR. Conclusions: The intraoperative multimode navigation appeared to be safe and effective when used in EES for GPA with higher GTR and lower residual tumor volume.

Recognizing facial expressions is crucial for adaptive social interaction. Prior empirical research on facial expression processing has primarily focused on isolated faces; however, facial expressions appear embedded in surrounding scenes in everyday life. In this study, we attempted to demonstrate how the online car-hailing scene affects the processing of facial expression. This study examined the processing of drivers' facial expressions in scenes by recording event-related potentials, in which neutral or happy faces embedded in online car-hailing orders were constructed (with type of vehicle, driver rating, driver surname, and level of reputation controlled). A total of 35 female volunteers participated in this experiment and were asked to judge which facial expressions that emerged in scenes of online car-hailing were more trustworthy. The results revealed an interaction between facial expression scenes, brain areas, and electrode sites in the late positive potential, which indicated that happy faces elicited larger amplitudes than did neutral ones in the parietal areas and that scenes with happy facial expressions had shorter latencies than did those with neutral ones. As expected, the late positive potential evoked by happy facial expressions in a scene was larger than that evoked by neutral ones, which reflected motivated attention and motivational response processes. This study highlights the importance of scenes as context in the study of facial expression processing.

Enhanced biological phosphorus removal (EBPR) process is susceptible to the changed operation condition, which results in an unstable treatment performance. In this work, long-term effect of coagulants addition, aluminum salt for the reactor R

In this paper, we study the higher-order generalized Ginzburg–Landau model which contributes to describing the propagation of optical solitons in fibers. By means of the Hirota bilinear method, the analytical solutions are obtained and the effect of relevant parameters is analyzed. Modulated by the near parity-time-symmetric potentials, the nonlinear modes with 5% initial random noise are numerically simulated to possess stable evolution. Furthermore, the evolution of nonlinear modes is displayed through the adiabatical change of some parameters. The investigation of the present work is intended as a contribution to the work for the higher-order generalized Ginzburg–Landau model.

Background Depression is an affective disorder characterized by low mood and loss of interest. So far, the mechanism of antidepressants commonly used in clinical practice has proved problematic, thus it is urgent to gain an updated understanding of the pathogenesis of depression and find potential therapeutic targets. As both functional brain imaging studies and autopsy reports indicated that there is indeed a loss of synapses in depressed patients, it is necessary to explore the mechanism of this process. Methods We firstly investigated the effect of CSDS (a mouse model of depression) on behaviors, synapses, microglia, and phagocytosis of synapses by microglia in mice. Then, to confirm the role of microglia in depression, we used minocycline, a microglial activation inhibitor, to study its effect on behaviors and phagocytosis of synapses in stressed mice. Results Our results show that the expression levels of PSD-95 in the hippocampus of CSDS-induced depression mice are significantly reduced, while the microglia are significantly activated. We co-labeled the synaptic protein PSD-95 with the microglia marker Iba-1, and found that the microglia in the hippocampus of stressed mice contained significantly more PSD-95 engulfed puncta, which revealed that microglia in stressed mice abnormally phagocytized synapses. Moreover, our results indicated that minocycline treatment dampened microglial activation, reduced synaptic loss, alleviated behavioral impairment, and reduced abnormal phagocytosis of synapses by microglia in stressed mice. Conclusions Under depressive pathological conditions, the activated microglia may abnormally engulf neuronal synapses causing synaptic loss. Our findings are important for the discovery of novel drugs for the treatment of depression.

Self-healing materials (SHMs) with unique mechanical and electronic properties are promising for self-reparable electronics and robots. However, the self-healing ability of emerging two-dimensional (2D) materials, for instance, MXenes, has not been systematically investigated, which limits their applications in self-healing electronics. Herein, we report the homogeneous self-healing assembly (homo-SHA) of MXene and the heterogeneous self-healing assembly (hetero-SHA) of MXene and graphene oxide (GO) under moisture treatments. The self-healing mechanism has been attributed to the hydration induced interlayer swelling of MXene and GO and the recombination of hydrogen bond networks after water desorption. The multiform hetero-SHA of MXene and GO not only enables facile fabrication of free-standing soft electronics and robots, but also endows the resultant devices with damage-healing properties. As proof-of-concept demonstrations, free-standing soft electronic devices including a generator, a humidity sensor, a pressure sensor, and several robotic devices have been fabricated. The hetero-SHA of MXene and GO is simple yet effective, it may pioneer a new avenue to develop miniature soft electronics and robots based on 2D materials.

The yolk–shell Bi@void@SnO2 photocatalyst was synthesized via a step-by-step process. The composition, morphology, optical and photoelectrochemical properties as well as the surface chemical composition and states of the samples were characterized by X-ray diffraction, transmission electron microscopy, UV–Vis diffuse reflectance spectra, electrochemical impedance spectra and X-ray photoelectron spectrometer, respectively. The tetracycline has been used to evaluate the photocatalytic activities of the as-synthesized samples. Compared with the degradation efficiency of 16.33% for pure Bi and almost nothing for SnO2 under visible light irradiation, the as-developed Bi@void@SnO2 photocatalyst possesses 81.81% of degradation efficiency. Meanwhile, the light absorption of the as-developed yolk–shell composites is broadened from ultraviolet to visible light comparing to pure SnO2 due to the surface plasmon resonance effect of Bi spheres. Moreover, the superoxide radicals, especially in holes, play leading roles during the photocatalytic degradation process. In addition, the decomposition mechanism of the as-fabricated composites for tetracycline is analyzed in detail.

Zn2SnO4/few-layer boron nitride nanosheets (FBNNS) hybrids were synthesized via a one-step hydrothermal method. The structures, morphology, optical properties, electron transformation and separation of the as-prepared products were characterized by X-ray diffraction, transmission electrical microscopy, UV-vis diffuse reflectance spectroscopy and electrochemical impedance spectroscopy, respectively. Rhodamine B was used to evaluate the photocatalytic activities of the as-prepared samples under visible light illumination. The photocatalytic mechanism was also explored. Experimental results showed that the degradation efficiency of rhodamine B was firstly increased and then decreased with increasing the usage amount of FBNNS. When it was 9 wt% based on the weight of Zn2SnO4, the degradation efficiency of the as-prepared Zn2SnO4/FBNNS-9 wt% composites reached to the maximum of 97.5% in 180 min, which was higher than 39.2 % of pure Zn2SnO4. Moreover, the holes played mainly active roles in photocatalytic reaction process. In addition, the as-prepared hybrids could enhance the separation efficiency of photoexcited carriers compared to pure Zn2SnO4.

The AgI/2D-La2Ti2O7 hybrids were obtained via a facile method at room temperature. Rhodamine B, as an organic dye, was used to determine the photocatalytic activity of the samples. The photocatalytic degradation mechanism was also analyzed. Experimental results display that AgI can broaden the light absorption of La2Ti2O7 under the visible light irradiation. The photocatalytic degradation efficiency of the as-synthesized hybrids appears the tendency of first increasing and then decreasing with increasing the usage of La2Ti2O7. When the usage of La2Ti2O7 is 10%, within 60 min, the as-synthesized hybrids possess the maximum of 93.1%. This is higher than 2.1% of La2Ti2O7 and 80.9% of AgI. Moreover, the improved photocatalytic activity can be attributed to AgI particles conjugating with 2D-La2Ti2O7 nanosheets via chemical-bonds, which can enhance the separation and transformation of the photo-generated holes and electrons. In addition, the dominating role is superoxide radicals during the photocatalytic process.

In the present work, wrinkled n-type WS2 nanosheets were synthesized and then used to construct the In2.77S4/WS2 p-n heterojunction photocatalyst. Experimental results reveal that the as-prepared hybrids present excellent photocatalytic activity for Cr(VI) reduction and tetracycline oxidation under visible and infrared light irritation. The photocatalytic efficiency of the as-prepared catalysts is found to increase initially followed by the decrease with the more weight content of WS2. When WS2 is up to 4 wt%, the as-prepared photocatalysts exhibit the highest photocatalytic activity, and are capable of reducing 99.1% of Cr(VI) in 60 min and oxidizing 87.5% of tetracycline in 20 min, much higher than 86.6 and 40.0% of pure In2.77S4, respectively. This enhanced photocatalytic activity is attributed to the construction of In2.77S4/WS2 p-n heterojunction between p-In2.77S4 and n-WS2. The detailed clarification of photocatalytic mechanism is also elaborated in the paper.

Full-spectrum-responsive AgI/WS2 composites as an efficient photocatalyst have been synthesised by an in-situ growth of AgI on the surfaces of WS2 nanosheets. The photocatalytic activities of the samples were evaluated by degradation of rhodamine B dilute solution under visible light irradiation. Experimental results showed that the introduction of WS2 nanosheets could enhance light absorption, photocatalytic activity, and recyclability of the pure AgI in the region of visible and infrared light. Moreover, the degradation efficiency of the as-synthesised AgI/WS2 composites exhibited the trend of first increased and then decreased with increasing the amount of WS2 nanosheets. When the usage of WS2 nanosheets was 7 wt%, the as-prepared composites possessed the maximum of 91.2% in 30 min. Furthermore, after three cycles of degradation, it could still degrade 89.0% of rhodamine B, obviously higher than 11.4% of pure AgI. In addition, a possible degradation mechanism of the as-synthesised AgI/WS2 hybrids was provided.