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Rapid screening for foodborne pathogens is crucial for food safety. A rapid and one-step electrochemical sensor has been developed for the detection of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium). Through the construction of aptamer/two-dimensional carboxylated Ti3C2Tx (2D C-Ti3C2Tx)/two-dimensional Zn-MOF (2D Zn-MOF) composites, the recognition elements, signal tags, and signal amplifiers are integrated on the electrode surface. Pathogens are selectively captured using the aptamer, which increases the impedance of the electrode surface，leads to a decrease in the 2D Zn-MOF current. Bacteria can be rapidly quantified using a one-step detection method and the replacement of aptamers. The detection limits for E. coli, S. aureus, and S. typhimurium are 6, 5, and 5 CFU·mL-1, respectively. The sensor demonstrated reliable detection capabilities in real-sample testing. Therefore, the one-step sensor based on the 2D Zn-MOF and 2D C-Ti3C2Tx has significant application value in the detection of foodborne pathogens.

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Objective: To investigate the long-term effectiveness of Ni-Ti memory alloy tripod fixator in the treatment of Kienböck disease. Methods: The clinical data of 22 patients with Kienböck disease who were treated with Ni-Ti memory alloy tripod fixator between January 2011 and September 2013 and followed up more than 10 years was retrospectively analyzed. There were 14 males and 8 females with an average age of 45 years (range, 20-64 years). The Lichtman staging was stage Ⅲb. According to AO/Association for the Study of Internal Fixation (AO/ASIF) classification, there were 6 cases of type B1, 2 cases of type B2, 10 cases of type B3, and 4 cases of type C2. The disease duration ranged from 18 to 50 months, with an average of 30.7 months. The operation time, intraoperative blood loss, and complications were recorded. Wrist height ratio and scapholunate angle were measured by wrist anteroposterior and lateral X-ray films before and after operation. The grip strength of bilateral hands was measured by Jamar dynamometer. The wrist pain was evaluated by visual analogue scale (VAS) score, and the wrist function was evaluated by Mayo score, and the radial deviation, ulnar deviation, dorsiflexion, and palmar flexion range of motion of wrist were measured. Results: The operation time was 45-60 minutes, with an average of 52.21 minutes; the intraoperative blood loss was 50-60 mL, with an average of 58.63 mL. No nerve or blood vessel injury occurred during operation. All patients were followed up 10-13 years (mean, 11.3 years). X-ray films at 3 months after operation showed that the density of lunate bone was lower than that before operation. Satisfactory fusion of the scapho-trapezio-trapezoeid joint was achieved at 3-6 months after operation (mean, 4.5 months), and the wrist height ratio and the scapholunate angle after fusion significantly improved when compared with those before operation ( P<0.05). Wrist pain relieved, scaphoid rotation and dislocation improved, and no radiocarpal joint degeneration was found during follow-up, and no internal fixator loosening, breakage, or lunate bone necrosis occurred. At last follow-up, the wrist radial deviation, ulnar deviation, dorsiflexion, and palmar flexion range of motion, VAS score, and grip strength of the affected side significantly improved when compared with those before operation ( P<0.05); the grip strength of the affected side recovered to 99.00%±1.25% of the healthy side. Mayo score ranged from 72 to 93, with an average of 85; 14 cases were rated as excellent, 5 good, and 3 satisfactory, the excellent and good rate was 86.4%. Conclusion: In the treatment of stage Ⅲb Kienböck's disease, the scapho-trapezio-trapezoeid joint usion using Ni-Ti memory alloy tripod fixator can effectively reduce pain, improve hand function, and prevent further deterioration, and achieve good long-term effectiveness.

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Modifying photoanodes with metal-organic frameworks (MOFs) as oxygen evolution reaction (OER) cocatalysts has emerged as a promising approach to enhance the efficiency of photoelectrochemical (PEC) water oxidation. However, designing OER-active MOFs with both high photo- and electrochemical stability remains a challenge, limiting the advancement of this research. Herein, we present a facile method to fabricate a MOF-modified photoanode by directly loading a pentanuclear Co-based MOF (Co-MOF) onto the surface of a Ti-doped hematite photoanode (Ti:Fe2O3). The resulting Co-MOF/Ti:Fe2O3 modified photoanode exhibits an enhanced photocurrent density of 1.80 mA∙cm-2 at 1.23 V, surpassing those of the Ti:Fe2O3 (1.53 mA∙cm-2) and bare Fe2O3 (0.59 mA∙cm-2) counterparts. Additionally, significant enhancements in charge injection and separation efficiencies, applied bias photon-to-current efficiency (ABPE), incident photon to current conversion efficiency (IPCE), and donor density (Nd) were observed. Notably, a minimal photocurrent decay of only 5% over 10 h demonstrates the extraordinary stability of the Co-MOF/Ti:Fe2O3 photoanode. This work highlights the efficacy of polynuclear Co-based MOFs as OER cocatalysts in designing efficient and stable photoanodes for PEC water splitting applications.

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Improving the charge separation, charge transfer, and effective utilization is crucial in a photocatalysis system. Herein, we prepared a novel direct Z-scheme NH2-MIL-125(Ti)@FeOCl (Ti-MOF@FeOCl) composite photocatalyst through a simple method. The prepared composite catalyst was utilized in the photo-Fenton degradation of Rhodamine B (RhB) and ciprofloxacin (CIP). The Ti-MOF@FeOCl (10FeTi-MOF) catalyst exhibited the highest catalytic performance and degraded 99.1 and 66% of RhB and CIP, respectively. However, the pure NH2-MIL-125(Ti) (Ti-MOF) and FeOCl catalysts achieved only 50 and 92% of RhB and 50 and 37% of CIP, respectively. The higher catalytic activities of the Ti-MOF@FeOCl composite catalyst could be due to the electronic structure improvements, photoinduced charge separations, and charge transfer abilities in the catalyst system. The composite catalysts have also enhanced adsorption and visible light-responsive properties, allowing for efficient degradation. Furthermore, the electron paramagnetic resonance (EPR) signals, the reactive species trapping experiments, and Mott-Schottky (M - S) measurements revealed that the photogenerated superoxide radical (•O2-), hydroxyl radical (•OH), and holes (h+) played a vital role in the degradation process. The results also demonstrated that the Ti-MOF@FeOCl heterojunction composite catalysts could be a promising photo-Fenton catalyst system for the environmental remediation. Environmental implications The discharging of toxic contaminants such as organic dyes, antibiotics, and other emerging pollutants to the environment deteriorates the ecosystem. Specifically, the residues of organic pollutants recognized as a threat to ecosystem and a cause for carcinogenic effects. Among them, ciprofloxacin is one of antibiotics which has biological resistance, and metabolize partially in the human or animal bodies. It is also difficult to degrade ciprofloxacin completely with traditional treatment methods. Similarly, organic dyes are also toxic and a cause for carcinogenic effects. Therefore, effective degradation of organic pollutants such as RhB and ciprofloxacin with appropriate method is crucial.

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Cubic hollow-structured NiCo-LDH was synthesized using a solvothermal method. Subsequently, clay-like Ti3C2Tx MXenes were electrostatically self-assembled with NiCo layered double hydroxides (NiCo-LDH) to form composites featuring three-dimensional porous heterostructures. The composites were characterized using SEM, TEM, XRD, XPS, and FT-IR spectroscopy. Ti3C2Tx MXenes exhibit excellent electrical conductivity and hydrophilicity, providing abundant binding sites for NiCo-LDH, thereby promoting an increase in ion diffusion channels. The formation of three-dimensional porous heterostructural composites enhances charge transport, significantly improving sensor sensitivity and response speed. Consequently, the sensor demonstrates excellent electrochemical detection capability for quercetin (Qu), with a detection range of 0.1-20 µM and a detection limit of 23 nM. Additionally, it has been applied to the detection of Qu in natural plants such as onion, golden cypress, and chrysanthemum. The recovery ranged from 97.6 to 102.28%.

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The Ti3C2 quantum dots (QDs)/oxygen-vacancy-rich BiOBr hollow microspheres composite photocatalyst was prepared using solvothermal synthesis and electrostatic self-assembly techniques. Together, Ti3C2QDs and oxygen vacancies (OVs) enhanced photocatalytic activity by broadening light absorption and improving charge transfer and separation processes, resulting in a significant performance boost. Meanwhile, the photocatalytic efficiency of Ti3C2 QDs/BiOBr-OVs is assessed to investigate its capability for oxygen evolution and degradation of tetracycline (TC) and Rhodamine B (RhB) under visible-light conditions. The rate of oxygen production is observed to be 5.1 times higher than that of pure BiOBr-OVs, while the photocatalytic degradation rates for TC and RhB is up to 97.27% and 99.8%, respectively. The synergistic effect between Ti3C2QDs and OVs greatly enhances charge separation, leading to remarkable photocatalytic activity. Furthermore, the hollow microsphere contributes to the enhanced photocatalytic performance by facilitating multiple light scatterings and providing ample surface-active sites. The resultant Ti3C2QDs/BiOBr-OVs composite photocatalyst demonstrates significant potential for environmental applications.

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Photocatalytic fixation of nitrogen to ammonia represents an attractive alternative to the Haber-Bosch process under ambient conditions, and the performance can be enhanced by defect engineering of the photocatalysts, in particular, formation of shallow energy levels due to oxygen vacancies that can significantly facilitate the adsorption and activation of nitrogen. This calls for deliberate size engineering of the photocatalysts. In the present study, pyrochlore Bi2Ti2O7 quantum dots and (bulk-like) nanosheets are prepared hydrothermally by using bismuth nitrate and titanium sulfate as the precursors. Despite a similar oxygen vacancy concentration, the quantum dots exhibit a drastically enhanced photocatalytic performance toward nitrogen fixation, at a rate of 332.03 µmol g-1 h-1, which is 77 times higher than that of the nanosheet counterpart. Spectroscopic and computational studies based on density functional theory calculations show that the shallow levels arising from oxygen vacancies in the Bi2Ti2O7 quantum dots, in conjunction with the moderately constrained quantum confinement effect, facilitate the chemical adsorption and activation of nitrogen.

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Porous Ti addresses the longstanding orthopedic challenges of aseptic loosening and stress shielding. This work expands on the evolution of porous Ti with the manufacturing of hierarchically porous, low stiffness, ductile Ti scaffolds via direct-ink write (DIW) extrusion and sintering of inks containing Ti and NaCl particles. Scaffold macrochannels were filled with a subtherapeutic dose of recombinant bone morphogenetic protein-2 (rhBMP-2) alone or co-delivered within a bioactive supramolecular polymer slurry (SPS) composed of peptide amphiphile nanofibrils and collagen, creating four treatment conditions (Ti struts: microporous vs. fully dense; BMP-2 alone or with SPS). The BMP-2-loaded scaffolds were implanted bilaterally across the L4 and L5 transverse processes in a rat posterolateral lumbar fusion model. In-vivo bone growth in these scaffolds is evaluated with synchrotron X-ray computed microtomography (µCT) to study the effects of strut microporosity and added biological signaling agents on the bone formation response. Optical and scanning electron microscopy confirms the ∼100µm space-holder micropore size, high-curvature morphology, and pore fenestrations within the struts. Uniaxial compression testing shows that the microporous strut scaffolds have low stiffness and high ductility. A significant promotion in bone formation was observed for groups utilizing the SPS, while no significant differences were found for the scaffolds with the incorporation of micropores. STATEMENT OF SIGNIFICANCE: By 2050, the anticipated number of people aged 60 years and older worldwide is anticipated to double to 2.1 billion. This rapid increase in the geriatric population will require a corresponding increase in orthopedic surgeries and more effective materials for longer indwelling times. Titanium alloys have been the gold standard of bone fusion and fixation, but their use has longstanding limitations in bone-implant stiffness mismatch and insufficient osseointegration. We utilize 3D-printing of titanium with NaCl space holders for large- and small-scale porosity and incorporate bioactive supramolecular polymers into the scaffolds to increase bone growth. This work finds no significant change in bone ingrowth via microporosity but significant increases in bone ingrowth via the bioactive supramolecular polymers in a rat posterolateral fusion model.

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Commercially pure titanium (c.p. Ti) and Ti6Al4V alloys are the most widely used metallic biomaterials in the biomedical sector. However, their high rigidity and the controversial toxicity of their alloying elements often compromise their clinical success. The use of porous ß-Titanium alloys is proposed as a solution to these issues. In this regard, it is necessary to implement economic, repetitive, and non-destructive measurement techniques that allow for the semi-quantitative evaluation of the chemical nature of the implant, its microstructural characteristics, and/or surface changes. This study proposes the use of simple measurement protocols based on electrical impedance measurements, correlating them with the porosity inherent to processing conditions (pressure and temperature), as well as the chemical composition of the implant. Results revealed a clear direct relationship between porosity and electrical impedance. The percentage and/or size of the porosity decrease with an increase in compaction pressure and temperature. Moreover, there is a notable influence of the frequency used in the measurements obtained. Additionally, the sensitivity of this measurement technique has enabled the evaluation of differences in chemical composition and the detection of intermetallics in the implants. For the first time in the literature, this research establishes relationships between stiffness and electrical impedance, using approximations and models for the observed trends. All the results obtained corroborate the appropriateness of the technique to achieve the real-time characterization of Titanium implants, in an efficient and non-invasive way.

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Herein, the few-layer Ti3C2Tx nanosheets loaded zeolitic imidazolate framework-67 nanoplates (Ti3C2Tx-ZIF-67) with a unique structure has been synthesized by surfactant control method, and then is employed as the core of precursor. A thin layer of polydopamine as the shell of precursor covered Ti3C2Tx-ZIF-67 forms a micro-nano reactor, leading to the confinement carbonization process. Consequently, a novel sensing material that few-layer Ti3C2Tx nanosheets loaded Co nanoparticles coated N-doped carbon (Ti3C2Tx-Co@NC) is obtained for the non-enzymatic determination of glucose. Owing to the impressive structure, the established glucose sensor based on Ti3C2Tx-Co@NC/glassy carbon electrode exhibits 0.5-100.0 µM of linear detection range and 66.8 nM of detection limit, which tends to detect low concentration of glucose. The synergistic few-layer Ti3C2Tx nanosheets, Co nanoparticles and NC are considered through a series of control experiments. First, few-layer Ti3C2Tx nanosheets provide a good transport channel for electron transfer, resulting in the lower steric hindrance. Second, Co nanoparticles provide active centers for the electrochemical detection. Third, N-doped carbon with conductivity and hydrophilia plays the role of stabilizing material structure to prevent the fragmentation of Ti3C2Tx and the agglomeration of Co nanoparticles. Such work proposes a confined strategy to develop MXene-ZIF-67-derived nanocomposite with high-performance structure.

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Kiwifruit, renowned for its antioxidant properties and nutritional richness, faces challenges in maintaining quality during transportation, often leading to suboptimal products reaching the market. To address this issue, a wireless transmission flexible ethylene monitoring device (WFEMD) was developed. This device comprises a flexible ethylene gas sensor and a signal transmission processing unit integrated with electronic components, enabling real-time monitoring capabilities. In this study, the catalytic activity of Pd and Pd/Ti heterojunctions was leveraged to enhance the ethylene gas sensing. The impact of Ti3C2Tx modified with varying masses of Pd nanoparticles on ethylene gas response levels was investigated. The signal transmission processing unit, fabricated by using the laser direct-writing method, was optimized to collect signals from the flexible ethylene gas sensor, convert them into corresponding ethylene concentrations, and transmit data via an antenna. By introducing a random forest (RF) classification algorithm, a remarkable 97.5% accuracy in predicting kiwifruit ripeness grades was achieved. The algorithm facilitated precise classification by collecting key parameters such as ethylene and CO2 during transportation. The WFEMD enables real-time acquisition of kiwifruit ethylene gas information, which is transmitted wirelessly for data visualization and traceability via mobile terminals. This empowers managers with timely insights into ethylene emissions and ripeness predictions, facilitating informed decision-making processes.

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The optimization of electromagnetic microwave absorbing (EMA) materials for radar stealth has been a continuous endeavor. However, meeting the defense requirements across multiple-frequency bands in increasingly complex and variable environments remains challenging. Drawing inspiration from the cytoskeleton-organelle structure, we designed and prepared a hierarchical MXene/NiFe2O4/calcined melamine foam (MNC) composite. The composite exhibits efficient and adjustable microwave absorption, infrared stealth, and solar absorption performance through the synergistic interaction of the components and the spatial effect of its novel microstructure. The composite achieves a minimum reflection loss of -58.57 dB and an effective absorption bandwidth (EAB) of 7.00 GHz, both of which can vary with the thickness. MNC also offers stable infrared stealth performance for heat sources ranging from 37 to 300 °C and high solar absorptivity up to 96.2%, promoting ambient-temperature-adaptive infrared stealth through electricity-sunlight cooperative regulation. With exceptional environmental adaptability characteristics such as photothermal conversion, lightness, elasticity, and hydrophobicity, the MNC composite holds promise as a multispectrum defense material for radar, infrared, and visible light for various forms of equipment, clothing, and wearables in harsh conditions.

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With the rising popularity of smart homes, there is an urgent need for devices that can perform real-time online detection of ammonia (NH3) concentrations for food quality measurement. In addition, timely warning is crucial to preventing individual deaths from NH3. However, few studies can realize continuous monitoring of NH3 with high stability and subsequent application validation. Herein, we report on an integrated device equipped with a nitrogen-doped Ti3C2Tx gas sensor that shows great potential in detecting food spoilage and NH3 leakage. The nitrogen doping results in the lattice misalignment of Ti3C2Tx, subsequently realizing effective barrier height modulation and enhanced charge transfer efficiency of nitrogen-doped Ti3C2Tx. Density functional theory calculations confirm the greatly enhanced adsorption of NH3 on nitrogen-doped Ti3C2Tx. Our work can inspire the design of efficient gas sensors for real-time and wireless detection of food spoilage and NH3 leakage.

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Metal Fused Filament Fabrication provides a simple and cost-efficient way to produce dense metal parts with a homogenous microstructure. However, current limitations include the use of hazardous and expensive organic solvents during debinding for flexible filaments the stiffness of filaments made from partly water-soluble binder systems. In this study, the influence of various additives on different partly water-soluble binder systems, with regard to the flexibility and properties of the final parts, was investigated. Furthermore, a method using dynamic mechanical analysis to quantify the flexibility of filaments was introduced and successfully applied. For the first time, it was possible to produce flexible, partly water-soluble filaments with 60 vol.% solid content, which allowed the 3D printing of complex small and large parts with a high level of detail. After sintering, density values of up to 98.9% of theoretical density were achieved, which is significantly higher than those obtained with existing binder systems.

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The modulation of electrical properties in composite materials is critical for applications requiring tailored electrical functionality, such as electromagnetic shielding and absorption. This study focuses on Ti64/B4C composites, a material combination promising enhanced electromagnetic properties. Laser direct manufacturing (LDM) was utilized to fabricate coaxial samples of Ti64 blended with TiB and TiC in various mass ratios, with sample thicknesses ranging from 0.5 mm to 3.5 mm. The electrical characterization involved assessing the dielectric and magnetic permeability, as well as impedance and reflectance, across a frequency spectrum of 2 to 18 GHz. The result reveals that TiC, when incorporated into Ti64, exhibits strong dielectric polarization and achieves a reflectivity as low as -40 dB between 7 and 14 GHz. Conversely, TiB demonstrates effective electromagnetic absorption, with reflectivity values below -10 dB in the frequency band of 8.5 to 11.5 GHz. The study also notes that a lower B4C content enhances electronic polarization and increases the dielectric coefficient, while higher contents favor ionic polarization. This shift can lead to a timing mismatch in the establishment of electron and ion polarization, resulting in a decreased dielectric coefficient. In addition, adjusting the B4C content in Ti64/B4C composites effectively modulates their electrical properties, suggesting a strategic approach to designing materials for specific electromagnetic functions.

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The mechanical properties of local materials subjected to various stress triaxialities were investigated via self-designed small punch tests and corresponding simulations, which were tailored to the geometry and notch forms of the samples. The finite element model was developed on the basis of the actual test method. After verifying the accuracy of the simulation, the stress, strain, and void volume fraction distributions of the Ti6Al4V titanium alloy under different stress states were compared and analyzed. The results indicate that the mechanical properties of the local material significantly differ during downward pressing depending on the geometric shape. A three-dimensional tensile stress state was observed in the center area, where the void volume fraction was greater than the fracture void volume fraction. The fracture morphology of the samples further confirmed the presence of different stress states. Specifically, the fracture morphology of the globular head samples (with or without U-shaped notches) predominantly featured dimples. Modifying the specimen's geometry effectively increased stress triaxiality, facilitating the determination of the material's constitutive relationship under varying stress states.

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Layered Ti3C2Tx MXene has been successfully intercalated and exfoliated with the simultaneous generation of a 3D silica network by treating its cationic surfactant intercalation compound (MXene-CTAB) with an alkoxysilane (TMOS), resulting in a MXene-silica nanoarchitecture, which has high porosity and specific surface area, together with the intrinsic properties of MXene (e.g., photothermal response). The ability of these innovative MXene silica materials to induce thermal activation reactions of previously adsorbed compounds is demonstrated here using NIR laser irradiation. For this purpose, the pinacol rearrangement reaction has been selected as a first model example, testing the effectiveness of NIR laser-assisted photothermal irradiation in these processes. This work shows that Ti3C2Tx-based nanoarchitectures open new avenues for applications that rely on the combined properties inherent to their integrated nanocomponents, which could be extended to the broader MXene family.

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This study aims to optimize the performance of CrN coatings deposited on WC cutting tools for machining Ti6Al4V alloy, where the formation of built-up edge (BUE) is a prevalent and critical issue. In-house CrN coatings were developed using the PVD (Physical Vapor Deposition) process, with variations in deposition parameters including nitrogen gas pressure, bias voltage, and coating thickness. A comprehensive experimental approach encompassing deposition, characterization, and machining performance evaluation was employed to identify the optimal deposition conditions. The results indicated that CrN coatings deposited at a nitrogen gas pressure of 4 Pa, a bias voltage of -50 V, and a thickness of 1.81 µm exhibited superior performance, significantly reducing BUE formation and tool wear. These optimized coatings demonstrated enhanced properties, such as a higher elastic modulus and a lower coefficient of friction, which contributed to improved tool life and machining performance. Comparative studies with commercial CrN coatings revealed that the in-house developed coatings outperformed the commercial variants by approximately 65% in tool life, owing to their superior mechanical properties and reduced friction. This research highlights the potential of tailored CrN coatings for advanced machining applications and emphasizes the importance of optimizing deposition parameters to achieve high-performance tool coatings.

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This study investigates the microstructural effects of process parameters on Ti6Al4V alloy produced via powder bed fusion (PBF) using laser beam melting (LB/M) technology. The research focuses on how variations in laser power, exposure velocity, and hatching distance influence the final material's porosity, microhardness, and microstructure. To better understand the relationships between process parameters, energy density, and porosity, a simple mathematical model was developed. The microstructure of the alloy was analyzed in the YZ plane using a confocal microscope. The study identified optimal parameters-302.5 W laser power, 990 mm/s exposure velocity, and 0.14 mm hatching distance-yielding the lowest porosity index of 0.005%. The material's average hardness was measured at 434 ± 18 HV0.5. These findings offer valuable insights for optimizing printing parameters to produce high-quality Ti6Al4V components using PBF-LB/M technology, shedding light on the critical relationship between process parameters and the resulting microstructure.

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In order to improve the wear and corrosion resistance of Ti6Al4V alloy, a Ti-N compound layer was formed on the alloy by plasma nitriding at a relatively low temperature (750 °C) and within an economical processing duration (4 h), in a mixture of NH3 and N2 gases with varying ratios. The influence of the gas mixture on the microstructure, phase composition, and properties of the Ti-N layer was investigated. The results indicated that the thickness of the nitrided layer achieved in a mixed atmosphere with optimal proportions of NH3 and N2 (with a ratio of 1:2) was substantially greater than that obtained in an atmosphere of pure NH3. This suggests that appropriately increasing the proportion of N2 in the nitriding atmosphere is beneficial for the growth of the nitrided layer. The experiments demonstrated that the formation of the surface nitrided layer significantly enhances the corrosion and wear resistance of the titanium alloys.