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Quorum sensing signal molecule is an important biomarker released by some microorganisms, which can regulate the adhesion and aggregation of marine microorganisms on the surface of engineering facilities. Thus, it is significant to exploit a convenient method that can effectively monitor the formation and development of marine biofouling. In this work, an advanced photoelectrochemical (PEC) aptamer biosensing platform was established and firstly applied for the rapid and ultrasensitive determination of N-(3-Oxodecanoyl)-l-homoserine lactone (3-O-C10-HL) released from marine fouling microorganism Ponticoccus sp. PD-2. The visible-light-driven Bi 2 WO 6 /Bi 2 S 3 heterojunction derived from metal-organic frameworks (MOFs) CAU-17 and self-screened aptamer were employed as the photoactive materials and bioidentification elements, respectively. Appropriate amount of MoS 2 quantum dots (QDs) conjugated with single-stranded DNA were introduced by hybridization to enhance the photocurrent response of the PEC biosensor. The self-screening aptamer can specifically recognize 3-O-C10-HL, accompanied by increasing the steric hindrance and forcing MoS 2 QDs to leave the electrode surface, resulting in an obvious reduction of photocurrent and achieving a dual-inhibition signal amplification effect. Under the optimized conditions, the photocurrent response of PEC aptasensor was linear with 3-O-C10-HL concentration from 1 nM to 10 μM, and the detection limit was as low as 0.26 nM. The detection strategy also showed a high reproducibility, superior specificity and good stability. This work not only provides a simple, rapid and ultrasensitive PEC aptamer biosensing strategy for monitoring quorum sensing signal molecules in marine biofouling, but also broadens the application of MOFs-based heterojunctions in PEC sensors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Hydrogels are an attractive category of biointerfacing materials with adjustable mechanical properties, diverse biochemical functions, and good ionic conductivity. Despite these advantages, their application in electronics has been restricted because of their lack of semiconducting properties, and they have traditionally only served as insulators or conductors. We developed single- and multiple-network hydrogels based on a water-soluble n-type semiconducting polymer, endowing conventional hydrogels with semiconducting capabilities. These hydrogels show good electron mobilities and high on/off ratios, enabling the fabrication of complementary logic circuits and signal amplifiers with low power consumption and high gains. We demonstrate that hydrogel electronics with good bioadhesive and biocompatible interface can sense and amplify electrophysiological signals with enhanced signal-to-noise ratios.

Organic photoelectrochemical transistor (OPECT) has shown substantial potential in the development of next-generation bioanalysis yet is limited by the either-or situation between the photoelectrode types and the channel types. Inspired by the dual-photoelectrode systems, we propose a new architecture of dual-engine OPECT for enhanced signal modulation and its biosensing application. Exemplified by incorporating the CdS/Bi 2 S 3 photoanode and Cu 2 O photocathode within the gate-source circuit of Ag/AgCl-gated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) channel, the device shows enhanced modulation capability and larger transconductance ( g m ) against the single-photoelectrode ones. Moreover, the light irritation upon the device effectively shifts the peak value of g m to zero gate voltage without degradation and generates larger current steps that are advantageous for the sensitive bioanalysis. Based on the as-developed dual-photoelectrode OPECT, target-mediated recycling and etching reactions are designed upon the CdS/Bi 2 S 3 , which could result in dual signal amplification and realize the sensitive microRNA-155 biodetection with a linear range from 1 fM to 100 pM and a lower detection limit of 0.12 fM.

Oxygen vacancy defects (OVs) are one of the main strategies for nanomaterials modification to improve the photoactivity, but current methods for fabricating OVs are usually complicated and harsh. It is important to develop simple, rapid, safe, and mild methods to fabricate OVs. By studying the effects of different weak reducing agents, the concentration of the reducing agent and the reaction time on fabrication of OVs, it is found that L-ascorbic acid (AA) gently and rapidly induces the increase of OVs in Bi 4 O 5 Br 2 at room temperature. The increased OVs not only improve the adsorption of visible light, but also enhance the photocurrent response. Based on this, the preparation of OVs in Bi 4 O 5 Br 2 is employed to the development of a photoelectrochemical biosensor for the detection of DNA demethylase of methyl-CpG binding domain protein 2 (MBD2). The biosensor shows a wide linear range of 0.1-400 ng mL -1 and a detection limit as low as 0.03 ng mL -1 (3σ). In addition, the effect of plasticizers on MBD2 activity is evaluated using this sensor. This work not only provides a novel method to prepare OVs in bismuth rich materials, but also explores a new novel evaluation tool for studying the ecotoxicological effects of contaminants., (© 2023 Wiley‐VCH GmbH.)

Marine microplastics are an increasingly big concern. We analyze the occurrence of microplastics in Alaska pollock ( Gadus chalcogrammus ) across 2+ to 12+ ages sampled from the Bering Sea. Results show that 85% of the fish have ingested microplastics and elder fish ingest more with over a third of microplastics in the 100- to 500-micrometer size range, indicating the prevalence of microplastics in Alaska pollock distributed in the Bering Sea. A positive linear relationship is obtained between fish age and microplastic size. Meanwhile, the number of polymer types increases in elder fish. The link between microplastic characteristics in Alaska pollock and the surrounding seawater suggests an extended spatial impact of microplastics. The impact of age-related microplastic ingestion on the population quality of Alaska pollock is still unknown. Therefore, we need to further investigate the potential impact of microplastics on marine organisms and the marine ecosystem, taking age as an important factor.

Optically active spin defects in van der Waals materials are promising platforms for modern quantum technologies. Here we investigate the coherent dynamics of strongly interacting ensembles of negatively charged boron-vacancy ([Formula: see text]) centers in hexagonal boron nitride (hBN) with varying defect density. By employing advanced dynamical decoupling sequences to selectively isolate different dephasing sources, we observe more than 5-fold improvement in the measured coherence times across all hBN samples. Crucially, we identify that the many-body interaction within the [Formula: see text] ensemble plays a substantial role in the coherent dynamics, which is then used to directly estimate the concentration of [Formula: see text]. We find that at high ion implantation dosage, only a small portion of the created boron vacancy defects are in the desired negatively charged state. Finally, we investigate the spin response of [Formula: see text] to the local charged defects induced electric field signals, and estimate its ground state transverse electric field susceptibility. Our results provide new insights on the spin and charge properties of [Formula: see text], which are important for future use of defects in hBN as quantum sensors and simulators., (© 2023. The Author(s).)

Background: We aimed to compare the difference between the therapeutic effects of percutaneous vertebroplasty (PVP) as well as PVP combined with erector spinae plane blocked (ESPB) in osteoporotic vertebral compression fractures (OVCFs) therapy., Methods: After the reception, 100 affected people to OVCFs were randomly divided into the PVP group as a control as well as the PVP + ESPB group as the observation, which included fifty affected people per group. The visual analog scale (VAS) for pain as well as the Oswestry Disability Index (ODI) per group was assessed before the operation, two hours after the operation, and when patients were discharged from the hospital. Operating time was also evaluated on the charged bulk of bone cement during the surgery, blood loss during the surgery, as well as operating costs for each group. Additionally, to assess differences, comparisons have been done among available groups in terms of ambulation as well as defecation or stool after the operation at the earlier time., Results: The PVP + ESPB category acquired lower VAS and ODI scores when assessments were processed 2 h after the operation and when they were discharged from a hospital. They also had earlier postoperative ambulation and defecation time than the category of PVP (p < 0.05). Regarding the other indicators, there did not show significant differences. Besides, no complications occurred within both group, either after the operation or when they discharge from the hospital., Conclusion: PVP + ESPB for OVCF is related to less VAS, further effective alleviation of pain, and fewer ODI values in affected people after the operation than only PVP. Besides, affected people can involve in ambulation more swiftly. The PVP + ESPB therapy improves the quicker recuperation of intestinal function as well as helps to improve the overall life quality of patients., (© 2023. The Author(s).)

Organic photoelectrochemical transistor (OPECT) biosensing represents a new platform interfacing optoelectronics and biological systems with essential amplification, which, nevertheless, are concentrated on depletion-type operation to date. Here, a polymer dot (Pdot)-gated accumulation-type OPECT biosensor is devised and applied for sensitive urea detection. In such a device, the as-designed Pdot/poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) is validated as a superior gating module against the diethylenetriamine (DETA) de-doped poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) channel, and the urea-dependent status of Pdots has been shown to be sensitively correlated with the device's response. High-performance urea detection is thus realized with a wide linear range of 1 μM-50 mM and a low detection limit of 195 nM. Given the diversity of the Pdot family and its immense interactions with other species, this work represents a generic platform for developing advanced accumulation-type OPECT and beyond.

Organic photoelectrochemical transistor (OPECT) bioanalytics has recently appeared as a promising route for biological measurements, which has major implications in both next-generation photoelectrochemical (PEC) bioanalysis and futuristic biorelated implementations. Via biological dissociation of materials, bioetching is a useful technique for bio-manufacturing and bioanalysis. The intersection of these two domains is expected to be a possible way to achieve innovative OPECT bioanalytics. Herein, we validate such a possibility, which is exemplified by alkaline phosphatase (ALP)-mediated bioetching of a CoOOH/BiVO 4 gate for a signal-on OPECT immunoassay of human immunoglobulin G (HIgG) as the model target. Specifically, target-dependent bioetching of the upper CoOOH layer could result into an enhanced electrolyte contact and light accessibility to BiVO 4 , leading to the modulated response of the polymeric poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) channel that could be monitored by the channel current. The introduced biosensor achieves sensitive detection of HIgG with high selectivity and sensitivity. This work features bioetching-enabled high-efficacy OPECT bioanalysis and is anticipated to serve as a generic protocol, considering the diverse bioetching routes.

A remarkable prediction of quantum field theory is that there are quantum electromagnetic fluctuations (virtual photons) everywhere, which leads to the intriguing Casimir effect. While the Casimir force between two objects has been studied extensively for several decades, the Casimir force between three objects has not been measured yet. Here, we report the experimental demonstration of an object under the Casimir force exerted by two other objects simultaneously. Our Casimir system consists of a micrometer-thick cantilever placed in between two microspheres, forming a unique sphere-plate-sphere geometry. We also propose and demonstrate a three-terminal switchable architecture exploiting opto-mechanical Casimir interactions that can lay the foundations of a Casimir transistor. Beyond the paradigm of Casimir forces between two objects in different geometries, our Casimir transistor represents an important development for controlling three-body virtual photon interactions and will have potential applications in sensing and information processing., (© 2022. The Author(s).)

Electron spins in van der Waals materials are playing a crucial role in recent advances in condensed-matter physics and spintronics. However, nuclear spins in van der Waals materials remain an unexplored quantum resource. Here we report optical polarization and coherent control of nuclear spins in a van der Waals material at room temperature. We use negatively charged boron vacancy ([Formula: see text]) spin defects in hexagonal boron nitride to polarize nearby nitrogen nuclear spins. We observe the Rabi frequency of nuclear spins at the excited-state level anti-crossing of [Formula: see text] defects to be 350 times larger than that of an isolated nucleus, and demonstrate fast coherent control of nuclear spins. Further, we detect strong electron-mediated nuclear-nuclear spin coupling that is five orders of magnitude larger than the direct nuclear-spin dipolar coupling, enabling multi-qubit operations. Our work opens new avenues for the manipulation of nuclear spins in van der Waals materials for quantum information science and technology., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Biofilms formed on metal surfaces strongly affect metallic instruments serving in marine environments. However, due to sampling difficulty, less has been known about the bacterial communities of the biofilm on metallic surfaces in hadal environments, so the failure process of these deep-sea metallic instruments influenced by microbial communities could be hardly predicted. In this research, seven alloys, including titanium, aluminum, and copper alloys, were exposed in Yap Trench hadal environment for 1 year. Thus, the communities of the biofilms formed on metallic surfaces at 5,772 m undersea in Yap Trench were initially reported in previous studies. Then, 16S rRNA gene sequencing was performed to visualize the in situ bacterial communities of the biofilms formed on titanium, aluminum, and copper alloys at 5,772 m undersea in Yap Trench. It was found that Proteobacteria was the dominant phylum in all samples, but distinct genera were discovered on various alloys. The titanium alloy provided a suitable substrate for a mutualistic symbiotic biofilm with abundant bacterial richness. Aluminum alloys without copper components showed the least bacterial richness and formed a cold-adapted and oligotrophic-adapted biofilm containing the genera Sulfurimonas and PS1 Clade , while copper-present alloys showed relatively high bacterial richness with copper-resistant or even copper-utilizing biofilms constituting the genera Stenotrophomonas , Burkholderia-Caballeronia-Paraburkholderia , and Achromobacter on the surfaces. Furthermore, among all the element components contained in alloys investigated in this research, copper element showed the strongest influences on the composition and function of microbial communities in the biofilms formed on various metallic surfaces., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zhai, Cao, Zhang, Ju, Chen, Duan and Sun.)

Plasmonic nanostructures with dual surface plasmon resonances capable of simultaneously realizing strong light confinement and efficient light radiation are attractive for light-matter interaction and nanoscale optical detection. Here, we propose an optical nanoantenna by adding gold nanoring to the conventional Fano-type resonance antenna. With the help of gold nanoring, the following improvements are simultaneously realized: (1). The near-field intensity of the Fano-type antenna is further enhanced by the Fabry Perot-like resonance formed by the combination of the gold nanoring and the substrate waveguide layer. (2). Directional radiation is realized by the collaboration of the gold nanoring and the Fano-type antenna, thus improving the collection efficiency of the far-field signal. (3). The multi-wavelength tunable performance of the Fano resonance antenna is significantly improved by replacing the superradiation mode in the Fano resonance with the dipole resonance induced by the gold nanoring. The optical properties of the nanoantennas are demonstrated by numerical simulations and practical devices. Therefore, the proposed optical nanoantenna provides a new idea for further improving the performance of conventional Fano-type nanoantennas and opens new horizons for designing plasmonic devices with enhancements in both near- and far-field functionalities, which can be applied in a wide range of applications such as surface-enhanced spectroscopy, photoluminescence, nonlinear nanomaterials/emitters and biomedicine sensing.

The binding interaction between emerging pollutant polyvinyl chloride microplastics (PVC MPs) and bovine serum albumin (BSA) was studied by fluorescence spectroscopy, resonance scattering spectroscopy (RLS), UV-visible (UV-vis) absorption spectroscopy, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. Fluorescence results revealed that the fluorescence quenching of BSA induced by PVC MPs was originated from the formation of BSA-PVC complex in static quenching mode. According to Stern-Volmer equation, the binding constants (K a ) between PVC MPs and BSA at different temperatures were obtained, and the number of binding sites was 1.62. The thermodynamic parameters, enthalpy change (ΔH), entropy change (ΔS), and free energy change (ΔG) were calculated to be - 41.77 kJ mol -1 , 43.17 J mol -1 K -1 , and - 54.63 kJ mol -1 via Van't Hoff equation, indicating electrostatic interaction played a key role in the formation of BSA-PVC complex spontaneously. In addition, the alterations of microenvironment and secondary structure in BSA induced by PVC MPs were further confirmed by synchronous fluorescence spectra, UV-vis, FT-IR, and CD. This work not only provides further information for better understanding the binding interaction of PVC MPs with BSA, but also elucidates the potential biological toxicity of MPs at a molecular level.

Mechanochromic luminescence materials have attracted rapidly growing interest. Nevertheless, the designed synthesis of such materials remains a challenge, and there have been few examples based on weak intramolecular interactions. Herein, we report a new approach for preparing mechanochromic luminescence materials of Cu(I) complexes, i.e., constructing a photoluminescence system that bears a large coplanar multinuclear Cu(I) unit showing weak intramolecular π···π interactions with the planar rings of the coordinated ligands in the molecule. Using it, a series of novel mechanochromic luminescent tetranuclear Cu(I) complexes have been successfully designed and synthesized. As revealed by single-crystal X-ray crystallography, these Cu(I) complexes share an identical {Cu 4 [μ 3 -η 2 (N,N),η 1 (N),η 1 (N)-pyridyltetrazole] 2 } 2+ planar fragment whose coplanar pyridyl rings exhibit weak intramolecular π···π interactions with the phenyl rings of the coordinated phosphine ligands in the molecule. All of these Cu(I) complexes exhibit reversible mechanochromic luminescence, which can be attributed to the change in the rigidity of the molecular structure resulting from the disruption and restoration of intramolecular π···π interactions between the pyridyl and phenyl rings triggered by grinding and CH 2 Cl 2 vapor, as supported by powder X-ray diffraction and Fourier transform infrared spectrometry. In addition, the results might provide a new route for developing mechanochromic luminescence materials of Cu(I) complexes for intelligent responsive luminescent devices.

In this work, a novel plasmonic Z-scheme Ag@AgVO 3 /BiVO 4 heterostructure was developed by a topotactic ion exchange-reduction strategy followed with an in-situ growth process. The ternary heterostructure were composed of AgVO 3 nanobelts (NBs) loading with BiVO 4 nanosheets (NSs) and Ag nanoparticles (NPs), which grew in-situ on the surface of AgVO 3 NBs via an topotactic transformation with the assistance of polyvinylpyrrolidone (PVP). Besides, PVP can not only realize the recycle of noble metal Ag but also induce a SPR effect in the composite. Experimental results indicated that the Ag@AgVO 3 /BiVO 4 composites displayed an significantly enhanced photocatalytic activity under visible light irradiation compared to AgVO 3 , Ag@BiVO 4 and AgVO 3 /BiVO 4 . The BiVO 4 content in the composite played a key role in controlling the morphology and photocatalytic activity of Ag@AgVO 3 /BiVO 4 heterostructure. Among the as-prepared photocatalysts, Ag@AgVO 3 /BiVO 4 -0.2 exhibited the highest photocatalytic performance and stability towards the degradation of rhodamine B (RhB) and disinfection of Escherichia Coli (E. coli). In addition, a possible Z-scheme photocatalytic mechanism was proposed based on the active species trapping experiments, demonstrating that the photogenerated holes (h + ) and O 2 - radicals were the dominating active species. The Z-scheme charge carrier migration mechanism, SPR effect of Ag NPs, large specific surface area combined with the stable heterostructure, resulted in the highly efficient transfer and the separation of photoinduced electrons and holes, which further contributed to the superior photocatalytic activity of Ag@AgVO 3 /BiVO 4 . This work is expected to inspire further attempts for the construction of novel Z-scheme photocatalysts with enhanced photocatalytic performances for potential application in the field of energy and environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

CoMoO 4 materials were prepared through a simple hydrothermal method and developed as highly efficient peroxidase mimics for colorimetric determination of H 2 O 2 . Based on the different experimental conditions in the synthesis process, the CoMoO 4 materials present distinct morphologies, structures, surface properties, and peroxidase mimetic activities. Among them, CoMoO 4 nanobelts (NBs) display the best intrinsic peroxidase mimetic abilities due to the high-energy (100) facet exposed, more Co active sites at (100) facet, more negative potential, and larger specific surface area. It can efficiently catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H 2 O 2 to generate a blue oxide. In view of the excellent peroxidase mimetic catalytic activity of CoMoO 4 NBs, a rapid, convenient, and ultrasensitive method was successfully established for the visual and colorimetric determination of H 2 O 2 . The method exhibits good selectivity, practicability, stability, and reusability, and has a detection limit of 0.27 μM. The peroxidase mimetic catalytic mechanism of CoMoO 4 NBs was illustrated according to the kinetic and active species trapping experiments. The method has a good potential for rapid and sensitive determination of H 2 O 2 for biomedical analysis. Graphical abstract Schematic presentation of the process of CoMoO 4 nanobelts catalyzing the oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H 2 O 2 to generate a typical blue color, which can be applied in rapid and ultrasensitive detection of H 2 O 2 visually.

Four kinds of Ag 3 PO 4 materials were prepared by controlling the experimental conditions, which were developed as oxidase mimics. Experimental results showed that different synthesis methods led to distinct crystal structures, morphologies, and surface properties, which contributed to diverse oxidase-like activities of Ag 3 PO 4 materials. Among them, Ag 3 PO 4 microcubes (APMCs) can efficiently catalyze the oxidation of colorless 3,3',5,5'-tetramethylbenzidine in the presence of dissolved oxygen to form a blue-colored oxide, presenting the best intrinsic oxidase mimetic ability. The higher-energy [110] facets with more oxygen vacancies exposed and more active sites coupled with more negative charge and larger specific surface area of APMCs contributed to its enhanced oxidase mimetic performance. Besides, mercury ions were proved to remarkably and selectively stimulate the oxidase-like ability of APMCs owing to the formation of Ag-Hg amalgam on its surface. Based on the stimulating effect of Hg 2+ towards APMCs, a simple and rapid method for colorimetric determination of Hg 2+ was thus established via the significant signal amplification and megascopic color variation. Under the optimal conditions, the sensing system showed a good linear relationship ranging from 0.1 to 7.0 μM and a detection limit of 20 nM for Hg 2+ , exhibiting high selectivity and good colour stability. Moreover, the colorimetric method was successfully applied to determine Hg 2+ in real water samples. Considering these advantages, the developed colorimetric sensing system is expected to hold bright prospects for trace determination of Hg 2+ in biological, environmental, and food samples. Graphical abstract The preparation process of Ag 3 PO 4 materials and Hg 2+ -stimulated enhanced oxidase-like ability of Ag 3 PO 4 microcubes in catalyzing the oxidation of TMB to generate a typical blue color, which can be applied in rapid and ultrasensitive detection of Hg 2+ visually.

Torque sensors such as the torsion balance enabled the first determination of the gravitational constant by Henri Cavendish 1 and the discovery of Coulomb's law. Torque sensors are also widely used in studying small-scale magnetism 2,3 , the Casimir effect 4 and other applications 5 . Great effort has been made to improve the torque detection sensitivity by nanofabrication and cryogenic cooling. Until now, the most sensitive torque sensor has achieved a remarkable sensitivity of 2.9 × 10 -24  N m Hz -1/2 at millikelvin temperatures in a dilution refrigerator 6 . Here, we show a torque sensor reaching sensitivity of (4.2 ± 1.2) × 10 -27  N m Hz -1/2 at room temperature. It is created by an optically levitated nanoparticle in vacuum. Our system does not require complex nanofabrication. Moreover, we drive a nanoparticle to rotate at a record high speed beyond 5 GHz (300 billion r.p.m.). Our calculations show that this system will be able to detect the long sought after vacuum friction 7-10 near a surface under realistic conditions. The optically levitated nanorotor will also have applications in studying nanoscale magnetism 2,3 and the quantum geometric phase 11 .

Metallic sodium, which has a suitable redox potential and high theoretical capacity, is regarded as an ideal anode material for rechargeable Na metal batteries. However, dendrite growth on sodium metal during cycling has seriously restricted its practical applications. Herein, we employed a low-cost and facile brushing method to fabricate a porous nano-SiO 2 coating, which can induce a relatively uniform distribution of Na + flux and suppress the growth of Na dendrites. The nano-SiO 2 coating with high porosity can decrease the Na stripping/plating overpotential (<50 mV) over 400 cycles at 5 mA cm -2 . Moreover, when coupled with a Na 3 V 2 (PO 4 ) 3 (NVP) cathode, the Na with SiO 2 coating (Na@SiO 2 ) composite anode shows a favorable suitability in a full cell. Compared with the one with a bare Na anode, the full cell with the Na@SiO 2 anode delivers a 27.8% higher discharge capacity (94.6 vs. 74 mA h g -1 at 1C) after 1000 cycles., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Hydrogen sulfide (H 2 S) is a kind of gaseous signal molecule in many physiological processes. In order to detect H 2 S, a novel "turn on" fluorescent probe 6,12-dihydroxyperylene-1,7-dione (DPD) was designed and synthesized. The probe DPD is fluorescence silence, while the addition of H 2 S induces an obvious green fluorescence with an obvious color change from dark blue to yellow-green. The probe shows excellent selectivity, fast response (2.5min) and linear curve (0-90μM) in wide effective pH range (4-10). Competition experiments are also revealed in corresponding studies and the detection limit is 3.6μM. The response mechanism is proved to be the reduction of the probe by H 2 S, which is confirmed by 1 H NMR. Furthermore, through the fluorescence turn-on signal toward H 2 S in Hela cells, probe DPD was successfully applied to monitor H 2 S in living Hela cells., (Copyright © 2019. Published by Elsevier B.V.)

Objectives:: A method was proposed to segment the tooth pulp cavity region in cone beam CT) images, which aimed to make the extraction process more efficient and generate more reliable results for further research., Methods:: Cone beam CT images of 50 teeth from 10 patients were randomly collected with the help of Peking University Hospital of Stomatology. All slice images have a ground truth tooth pulp cavity region delineated by two doctors manually. After necessary gamma transform in pre-processing stage, three kinds of information in an image such as greyscale, neighbour average greyscale and gradient were fused to search an optimal segmentation threshold by using plane intercept histogram of reciprocal cross entropy algorithm. With the optimal threshold, binarization was conducted and the tooth pulp cavity regions in slice images can be extracted. Qualitative and quantitative analyses compared to ground truth are involved with the evaluation criterion of average non-coincidence rate ( R ANOA ). Independent repeated experiments were carried out to test the stability of this segmentation method., Results:: Accurate and complete segmentation results are obtained. The proposed method reaches the lowest R ANOA values in most cases and owns more competitive robustness under various interferences compared with the other popular segmentation methods like reciprocal cross entropy method, active contour-based method, region growing method and level set method. Quantitative analysis verified the effectiveness of this method., Conclusions:: The proposed method can extract tooth pulp cavity regions from teeth efficiently. The segmentation results of this method are more accurate compared to other popular methods under different circumstances and can be used for subsequent applications.

Nanocrystals (NCs) of type Cu 2 ZnSn(S x Se 1-x ) 4 (CZTSSe) were prepared via a solvothermal approach. They are shown to be highly efficient peroxidase (POx) mimics for colorimetric detection of H 2 O 2 . By varying the molar ratio of S and Se during preparation, the NCs showed different crystal structures, morphologies, surface properties, and POx-like activities. Among them, the type CZTSSe-0.25 NCs exhibit the strongest POx-like activities towards the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine in the presence of H 2 O 2 to generate a blue product. The enhanced activity is attributed to its more negative potential and larger specific surface of the NCs. Based on these findings, a rapid and ultrasensitive method was developed for the visual and colorimetric determination of H 2 O 2 . The method is selective, and the NCs are reusable and long-term stable. The detection limit of H 2 O 2 is 50 nM. Kinetic and active species trapping experiments were performed to elucidate the POx-like mechanism of the NCs. Graphical abstract Schematic presentation of the process of Cu 2 ZnSn(S x Se 1-x ) 4 nanocrystals catalyzing the oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H 2 O 2 to induce a typical blue color reaction, which can be applied in colorimetric detection of H 2 O 2 .

MoS₂ quantum dots (QDs) functionalized g-C₃N₄ nanosheets (MoS₂@CNNS) were prepared through a protonation-assisted ion exchange method, which were developed as a highly efficient biomimetic catalyst. Structural analysis revealed that uniformly-dispersed MoS₂ QDs with controllable size and different loading amount grew in-situ on the surface of CNNS, forming close-contact MoS₂@CNNS nanostructures and exhibiting distinct surface properties. Compared to MoS₂ QDs and CNNS, the MoS₂@CNNS nanocomposites exhibited a more than four times stronger peroxidase-like catalytic activity, which could catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H₂O₂ to generate a blue oxide. Among the MoS₂@CNNS nanocomposites, MoS₂@CNNS(30) was verified to present the best intrinsic peroxidase-like performance, which could be attributed to the more negative potential and larger specific surface area. A simple, rapid and ultrasensitive system for colorimetric detection of H₂O₂ was thus successfully established based on MoS₂@CNNS, displaying nice selectivity, reusability, and stability. The detection limit of H₂O₂ could reach as low as 0.02 μM. Furthermore, the kinetic and active species trapping experiments indicated the peroxidase-like catalytic mechanism of MoS₂@CNNS. This work develops a novel, rapid, and ultrasensitive approach for visual assay of H₂O₂, which has a potential application prospect on clinical diagnosis and biomedical analysis.

An aptamer-based fluorescence assay for culture-independent detection of Pseudomonas aeruginosa was developed. This assay was enabled by highly specific aptamers conjugated with photoluminescent carbon dots (CDs) as the fluorescent probe and graphene oxide (GO) as the quencher. Specially, high-throughput sequencing was achieved during systematic evolution of ligands via exponential enrichment (SELEX) for accurate recognition of aptamers. This assay displayed high specificity towards P. aeruginosa and was resistant to interference by other ubiquitous bacteria including Escherichia coli , Bacillus subtilis , Staphylococcus aureus , Enterococcus faecalis , and Clostridium perfringens . After the conditions were optimized, this assay achieved a wide detection range for P. aeruginosa varying from 10 1 CFU mL -1 to 10 7 CFU mL -1 . Notably, it approached an excellent detection limit as low as 9 CFU mL -1 . Therefore, this fluorescence assay was considered successfully developed for highly sensitive detection of P. aeruginosa . This assay also detected the contamination of P. aeruginosa in tap water and commercial bottled water, thereby suggesting its potential application in real water samples., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Objective: To evaluate the effect of iron metabolism of preoperation on the length of intensive care unit (ICU) stay in liver transplant recipients., Methods: A retrospective study was conducted. 120 adult liver transplant recipients admitted to Tianjin First Central Hospital from September 2015 to September 2017 were enrolled. The basic data, model of end-stage liver disease (MELD) evaluation system score at admission; iron metabolism index, routine blood test, blood biochemistry, coagulation time and C-reactive protein (CRP) level within 24 hours after admission; intraoperative clinical indicators such as operation time, operation bleeding volume, red blood cells and fresh frozen plasma input volume, hot ischemia time, cold ischemia time, urine volume; and the length of ICU stay were collected. All patients were divided into iron deficiency group (ID group; serum ferritin < 100 μg/L, or serum ferritin 100-300 μg/L and transferrin saturation < 0.20) and non-iron deficiency group (non-ID group; serum ferritin > 300 μg/L, or serum ferritin 100-300 μg/L and transferrin saturation > 0.20) according iron deficiency standard. The indexes of iron metabolism, basic data and clinical indicators of two groups were compared. The correlation between serum ferritin level and the length of ICU stay was analyzed by Pearson correlation., Results: Compared with non-ID group, the levels of serum iron concentration and serum ferritin were significantly decreased in ID group [serum iron concentration (μmol/L): 3.50±1.62 vs. 14.50±2.31, serum ferritin (μg/L): 67.00±31.54 vs. 315.00±36.73, both P < 0.01], infusion volume of intraoperative red blood cells and fresh frozen plasma were significantly increased, and the length of ICU stay was significantly prolonged (days: 6.5±2.4 vs. 3.3±0.5, P < 0.01). There was no significant difference in transferrin saturation, CRP and other clinical indicators between the two groups. Correlation analysis showed that serum ferritin level was negative correlated with the length of ICU stay (r = -0.768, P < 0.001)., Conclusions: Preoperative iron deficiency in liver transplant recipients will lead to increased blood transfusion and prolonged length of ICU stays.

Objectives: A method was introduced for three-dimensional (3D) cone-beamCT (CBCT) images registration of temporomandibular joint (TMJ). This study aimed to provide quantitative and qualitative analysis of TMJ bone changes in two-dimensional (2D) and 3D and to provide the technique for computer-aided diagnosis of temporomandibular joint disorders in the future., Methods: 10 TMJ samples of six patients were obtained from Peking University Hospital of Stomatology. Four of the six patients imaged bilateral TMJs and the other two patients only imaged unilateral TMJ. Each sample consisted of two images from the same TMJ taken at different times. First, condyle and skull base were segmented semi-automatically for 3D model reconstruction. Then the segmented condyle and skull base were registered separately. Registration process can be divided into two processes of rough registration and fine registration. Rough registration step was achieved by selecting corresponding points manually and initialized fine registration. Condyle and skull base were fine registered by minimizing mean square error of condyle (MSE condyle ) and skull base (MSE skull ) respectively. Qualitative assessment of osseous component changes utilized 2D color-fused model and 3D surface-fused model and quantitative analyses the convergence of this method used the mean square error of the model (MSE model ). Independent repeated experiments were carried out to test the stability of our 3D registration method., Results: Sufficiently alignment was achieved. Osseous abnormality and morphology changes were displayed using fusion model. MSE model  of condylar registration and skull base registration declined 51.80% and 64.58% compared with that before registration. Quantitative analysis verified the stability of the method., Conclusions: The proposed method completed 3D TMJ registration for different physiological structure. The result of this method was accurate, reproducible and not relied on the experience of operators.

Andrographolide (AD) is the main compound distributed in medicinal herb Andrographis paniculata and exhibits anti-inflammatory activity. AD has been used for the treatment of multiple inflammatory diseases. However, the therapeutic value of AD on human rheumatoid arthritis (RA) remains unclear. In this study, we investigated the effects of AD on collagen-induced arthritis (CIA) and human RA synovial fibroblasts (RA-SFs). CIA mice were treated with AD (dissolved in 0.5% CMC-Na, 100 mg/kg per day) or vehicle (0.5% CMC-Na) daily by oral gavage for 2 weeks. The arthritis severity and joint destruction were assessed. Serum anti-collagen II antibody (anti-CII Abs) and cytokines were determined by ELISA. TNFα-stimulated human RA-SFs were treated with varying doses of AD for in vitro investigation. Results showed that AD significantly attenuated the arthritis severity and joint damage. AD treatment significantly reduced the production of serum anti-CII, TNFα, IL-1β, and IL-6. In vitro, AD decreased the secretion of IL-1β and IL-6 from TNFα-stimulated RA-SFs in a dose-dependent manner. AD treatment reduced the TNFα-induced phosphorylation of p38 MAPK and ERK1/2 in a dose-dependent manner. Thus, our findings suggest that AD confers protective effects on autoimmune arthritis through inhibiting MAPK pathways.

The thiophene-modified rhodamine 6G (GYJ) has been synthesized as a novel chemosensor. The sensor has sufficiently high selectivity and sensitivity for the detection of Fe 3+ and Al 3+ ions (M 3+ ) by fluorescence and ultraviolet spectroscopy with a strong ability for anti-interference performance. The binding ratio of M 3+ -GYJ complex was determined to be 2:1 according to the Job's plot. The binding constants for Fe 3+ and Al 3+ were calculated to be 3.91 × 10 8 and 5.26 × 10 8  M -2 , respectively. All these unique features made it particularly favorable for cellular imaging applications. The obvious fluorescence microscopy experiments demonstrated that the probes could contribute to the detection of Fe 3+ and Al 3+ in related cells and biological organs with satisfying resolution. Graphical abstract GYJ has high selectivity and sensitivity for the detection of Fe(III) and Al(III) with the binding ratio of 2:1.

In this article, a novel Ag 2 S nanoparticle-decorated MoS 2 composite (A@M) was synthesized through a facile in situ growth of the monoclinic crystallographic Ag 2 S on MoS 2 nanosheets. The A@M composite was used as a catalyst in water splitting which exhibits higher electrocatalytic and photoelectrocatalytic activity than the respective pure MoS 2 and Ag 2 S counterparts. Experimental results indicate that the as-prepared A@M composite with an optimal Ag 2 S/MoS 2 molar ratio of 16.30% (16%A@M) shows the best catalytic performance with low overpotentials (110 mV for V oc , 190 mV for onset overpotential, 208 mV for the current density of 20 mA cm -2 ), a small Tafel slope (42 mV dec -1 ), and a high photocurrent (82 μA cm -2 under an applied potential of 0.4 V). The enhanced electrocatalytic activity is associated with the improved electrical conductivity resulting from the stretched MoS 2 nanosheets and the enriched active sites due to the decorated Ag 2 S particles. The formation of a type II heterojunction structure at the interface between Ag 2 S and MoS 2 facilitates the separation of photogenerated charge carriers, and thus is responsible for the enhanced photoelectrocatalytic activity and photocatalytic H 2 production rate (628 μmol h -1 g -1 ). This work suggests a promising choice to overcome the intrinsic drawbacks of MoS 2 nanostructures for the application in hydrogen evolution.

In this paper, CeVO 4 materials were developed as highly efficient biomimetic catalysts for the first time to detect H 2 O 2 . These CeVO 4 materials were prepared by a facile hydrothermal method with the assistance of EDTA, exhibiting different morphologies, surface properties, and distinct peroxidase mimetic activities. Among them, CeVO 4 -2 nanorods (NRs) were proved to display the best intrinsic peroxidase-like property compared to other CeVO 4 samples due to their more negative potential and larger BET specific surface area, which could efficiently catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H 2 O 2 to generate a blue oxide. Based on the excellent peroxidase mimetic catalytic activity of CeVO 4 -2 NRs, a simple, convenient and visual H 2 O 2 detection system was successfully established. The detection limit of H 2 O 2 could reach as low as 0.07 μM. Moreover, the CeVO 4 -2 NR-based assay system presented an excellent selectivity, practicability, long-term stability, and reusability. The peroxidase-like catalytic mechanism of CeVO 4 -2 NRs was proposed on the basis of active species trapping experiments. This work provides a novel, convenient, rapid, and ultrasensitive system for the colorimetric detection of H 2 O 2 , which has a bright prospect in H 2 O 2 detection and biomedical analysis.

Unlabelled: Taiwan's skin banking program was initially set up to provide a ready source of cadaveric skin for patients with severe burns. However, human cadaveric skin may offer a useful alternative to conventional dressings in other wounds as well., Methods: In this retrospective review, cadaveric skin transplantation was used as temporary coverage in 145 patients with chronic ulcers, diabetic foot ulcers (DFU), necrotizing fasciitis, and acute traumatic wounds. Sex, age, number of debridements, and number of cadaveric skin transplantations were analyzed using statistical methods., Results: After clinical determination of engraftment 1 week after cadaveric skin allograft, skin samples harvested for histology in 15 cases revealed migration of epithelia from patient's skin to the surface of cadaver skin and the presence of granulation tissue in the base of the cadaver skin. All wounds exhibited good wound-bed preparation after cadaveric skin transplantation, and could eventually be resurfaced with a skin autograft., Conclusion: Human cadaveric skin, in addition to being the mainstay in burn therapy, is a good biological dressing for chronic ulcers, DFUs, necrotizing fasciitis, and acute traumatic wounds. .

Fournier gangrene is an acute and potentially fatal infection of the scrotum, perineum, and abdominal wall. It is characterized by necrotizing fasciitis with loss of subcutaneous tissue and skin. The aim of this study was to analyze the prognosis and treatment effectiveness of this fulminant infectious disease. Forty-one patients were admitted to our hospital with the diagnosis of Fournier gangrene between January 1998 and December 2006. The patients' age, sex, predisposing factors, duration of symptoms and hospital stay, time to operation, size of the skin defect, bacteria isolated, treatment modalities, and outcomes were reviewed. The data were analyzed by chi2 analysis and Student t test. A P-value <0.05 was considered significant. The mean age of the patients was 57.2 years. The most common predisposing factor was diabetes mellitus in 21 patients (51.2%), followed by cirrhosis of the liver, uremia, alcoholism, and underlying malignancy. The most common symptoms were fever (87.8%) and pain or swelling over the genital region (85.4%). The initial treatment included extensive debridement and open drainage. Time to operation ranged from 1 to 10 days. Reconstructive surgery was performed for 22 patients. The mortality rate was 19.5%. Delayed debridement was a significant factor affecting the survival rate. Our study is a retrospective study of patients with Fournier gangrene undergoing debridement and reconstructive procedure. Because of the fulminant course of Fournier gangrene, it may be difficult to design a prospective study. Fournier gangrene is a severe infectious disease with a high mortality rate. Early and aggressive debridement is a significant prognostic factor in the management of Fournier gangrene. Several reconstructive modalities are useful to correct the tissue defect. Early debridement and reconstructive surgery for wound coverage improve the quality of life.

Objective: To evaluate the feasibility of cone beam computed tomography (CBCT) for the evaluation of trabecular bone structure in mandibular condyle and to investigate the distribution of the trabecular bone structure within mandibular condyle., Methods: Eighty condyles from 40 healthy young volunteers (aged 20-32) were scanned by CBCT. A coronoid image was acquired of each condyle and divided into 8 regions where regions of interest were specified. After CBCT images were binarized, four morphological parameters including bone volume fraction, trabecular thickness, trabecular number and trabecular separation were computed., Results: All parameters were significantly different between the superior zone and middle/inferior zone of the condyle (P < 0.05). Superior zone showed the largest bone volume fraction (52.2%), the highest trabecular number (1.33 mm(-1)), the thinnest trabecular thickness (393.48 microm), and the smallest trabecular separation (361.59 microm). Inferior zone showed the smallest bone volume fraction (49.64%). These results were not significantly different between bilateral sides of the condyles (P > 0.05)., Conclusions: Trabecular bone structure was inhomogeneous within the condyle, but symmetrical between bilateral sides of the condyles. CBCT combined with image processing is a feasible tool in evaluating trabecular bone structure of human mandibular condyle.