Acid phosphatase (ACP) is a key biomarker for prostate disorders, hyperparathyroidism, and other metabolic diseases. However, current ACP assays are limited by complex protocols, bulky instrumentation, and poor stability under resource-limited conditions. Herein, we report a portable, smartphone-readable point-of-care testing (POCT) platform integrating bimetallic FeCo-MOF nanozymes entrapped in freeze-dried agarose hydrogel carriers for dual-mode (colorimetric-fluorometric) quantification of ACP in human serum. The FeCo-MOF catalyzes glucose oxidation to generate H2O2 and reactive oxygen species, converting o-phenylenediamine (OPD) to the chromogenic/fluorogenic product 2,3-diaminophenazine (DPA). ACP-mediated hydrolysis of sodium pyrophosphate (PPi) restores FeCo-MOF activity, enabling signal readout proportional to ACP concentration. Encapsulation of reagents within freeze-dried hydrogels significantly enhances substrate stability (89-100% activity retained at 4 °C for 30 days) and facilitates rapid reagent diffusion (<5 min). The 3D-printed device (∼1.3 kg) integrates a temperature control stage (±1 °C), dark chamber, dual-excitation light sources, and smartphone-based signal acquisition. Under optimized conditions (37 °C, 40 min and 75 °C, 8 min), the assay achieves linear ranges of 0.4-3.5 U/L (colorimetric) and 0.2-4.0 U/L (fluorometric), with LODs of 0.21 and 0.11 U/L, respectively. Results correlate strongly with conventional UV-vis and ratiometric fluorescence methods. Recovery in spiked serum samples ranges from 95 to 106%, with negligible interference from common serum constituents. This integrated POCT system offers a low-cost, user-friendly, and quantitatively reliable approach for ACP detection in decentralized settings.

Arsenic-containing anti-APL drugs ATO and RIF exhibit differential toxicity at therapeutic doses. In mouse heart, liver, spleen, lung and kidney tissues, iAsIII and DMAV are the predominant arsenic species with time-dependent enrichment, with oral RIF showing lower visceral arsenic accumulation than intravenous ATO after 7 days of administration.

In this work, effects of sintering temperature, holding time, and Ti content in the metal matrix on wear resistance of Cu–Ti/diamond composites were systematically investigated using Box-Behnken Design based on the Response Surface Methodology (RSM) for the first time. Analysis of Variance (ANOVA) identified Ti content and temperature as the dominating factors, although significant interplay between them was observed to jointly govern the formation kinetics of the interfacial TiC reaction layer. Based on the established high-precision quadratic regression model, the optimal processing parameters were determined to be 1323 K, 30 minutes, and 45 at. pct Ti. Validation experiments yielded a weight loss of 0.997 g under such conditions, representing a relative error of only 4.07 pct compared to the predicted value. Microstructural characterization at the interface confirmed the formation of a uniform reaction layer with a thickness of 2.2 μm. The surface morphology of the optimized sample after wear showed that diamond particles predominantly exhibited transgranular fracture during the wear process, which indicates a strong metallurgical bonding has been formed at the interface, boding well to enhance the overall wear resistance of targeted Cu–Ti/diamond composites. This study establishes quantitative process-interface-property relationships for Cu–Ti/diamond composites, providing a reliable methodological reference for the synergistic optimization of properties in sintered metal-matrix diamond composites.

Metal-organic frameworks (MOFs) are attractive optical sensing materials, yet their intrinsic frangibility and poor processability have hindered the fabrication of macro-scale optical device. Herein, a colorimetric sensor array (CSA) is designed by in situ growing and assembling lanthanide MOF (Isg-LnMOF) on a 3D-printed frame for the identification and detection of eight volatile organic compounds (VOCs). The 3D-printed frame was fabricated by a precursor ink containing organic ligands, alginate, deprotonation agent and commercial resins, and then immersed in a lanthanide ion solution to trigger in situ growth and assembly of LnMOF (Ln=Tb, Eu, Sm) through ion coordination and chelation. Compared to LnMOFs synthesized via various assembly methods, Isg-LnMOF exhibits a dense and uniform morphology, enhanced stability, and superior reproducibility (RSD=1.0−1.5%). Principal component analysis (PCA) and linear discriminant analysis (LDA) are employed for classification of eight VOCs and quantitative analysis of individual VOCs, respectively. The Isg-LnMOF CSA can unambiguously identify the eight VOCs, and achieves the detection limits of 2.6−5.1 ppm. The CSA also successfully discriminates binary VOCs mixtures and a simulated ternary industrial exhaust (acetone/benzene/toluene), with distinct clustering in PCA space. This demonstrates its potential as a colorimetric sensing platform for VOCs monitoring applications, including industrial emission control, indoor air quality assessment, and occupational exposure monitoring.

BACKGROUND:Microplastics (MPs) can adsorb and accumulate chromium and antibiotics in environments, releasing these pollutants in the human stomach and inducing potential health risks. Although simple static gastrointestinal models have been adopted to preliminarily evaluate the bioaccessibility of chromium-loaded MPs (Cr-MPs) by maintaining constant digestive parameters, they cannot faithfully replicate the fluid mechanics and dynamic physiological variations of real human gastric digestion. Moreover, current research lacks systematic exploration of antibiotic-modulated chromium adsorption on MPs and their combined toxicological effects during stomach digestion. RESULTS:A self-developed dynamic stomach model coupled with HPLC-ICPMS was adopted to explore chromium adsorption by three typical antibiotics-affected MPs and the gastric release and toxicity of Cr-MPs. Chromium species adsorption on PVC MPs is mainly physical, and antibiotics significantly promote chromium adsorption on MPs via multiple interfacial interactions. During gastric digestion, Cr(VI) on MPs was rapidly reduced to Cr(III) within 15 min, and antibiotic intervention reduced chromium release rate but increased total release amount. Both Cr(III) and Cr(VI) posed no non-carcinogenic hazards, while antibiotics elevated children's Cr(VI) carcinogenic risks from acceptable to significant levels. SIGNIFICANCE:This work systematically investigates the adsorption mechanism of chromium by MPs in the environment, the release and speciation transformation of chromium during gastric digestion, and the effects of antibiotics on the aforementioned processes. It supplies a reference for exploring the interactions between MPs, antibiotics, and metals in the human digestive system, offering scientific support for the accurate assessment of human health risks posed by MPs-bound heavy metal pollutants.

Integrating long-lived room-temperature phosphorescence (RTP) into nanozymes to build multifunctional nanozymes can benefit biomedical analysis by expanding sensing modes and developing advanced sensing strategies but it is challenging. Herein, a general strategy for fabricating phosphorescent nanozymes by anchoring Co-Nx active centers on SiO2 nanospheres with carbon dots (CDs) encapsulated inside (CDs@SiO2@Co) is developed for dual-mode colorimetric-phosphorescent detection of glutathione (GSH). Specifically, surface Co-Nx active centers enhanced O2 adsorption and activation (O2 to 1O2), providing oxidase-like activity to induce the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB), generating a distinct colorimetric signal. The SiO2 layer inhibited non-radiative transitions of the CDs to promote RTP, and spatially separated Co ions from CDs to prevent RTP quenching caused by Co-CD interactions, resulting in CDs@SiO2@Co with long-lived RTP (lifetime: 1.14 s), providing a phosphorescent channel free from autofluorescence interference. Upon introduction of GSH, the color product-oxidized TMB (oxTMB) was reduced, and the quenched RTP caused by the oxTMB internal filter effect was restored. Based on this principle, a sensitive and reliable dual-mode colorimetric-phosphorescent method was developed for detecting GSH in plasma and cells. Furthermore, owing to the tunable optical properties of CDs and the flexibility of substituting metal active centers, this strategy can be extended to construct various phosphorescent nanozymes with adjustable RTP emission wavelengths and diverse enzyme-like activities, advancing the development of nanozymes and bioanalytical platforms.

Perovskite oxides, with their flexible electronic structure and low cost, are highly attractive alternatives to noble metal catalysts for oxygen redox reactions (ORRs). Herein, we report LaNiO3 perovskite as an efficient ORR catalyst, where oxygen vacancies and oxygen-containing functional groups work synergistically. LaNiO3 was subjected to thermal shock in different media to introduce defects on the structural surface. Experimental results indicate that thermal shock in air creates oxygen vacancies on the catalyst surface, while thermal shock in aqueous solution increases the content of oxygen-containing functional groups (-OH) on the surface. The samples subjected to thermal shock exhibit superior ORR catalytic performance, with the limiting current density increasing from 4.2 mA cm-2 to 5.4 mA cm-2. This work provides a convenient and straightforward approach for constructing a series of materials enriched with surface defects.

Experimental teaching， serving as a bridge between theoretical knowledge and practical competence， can deepen students' understanding of theoretical concepts， and enhance their ability to solve complex problems， thereby playing a pivotal role in cultivating elite chemistry talents for the national innovation system. By understanding the laws of higher education development and innovative talent growth， the Chemistry Experiment Teaching Center of the College of Sciences at Northeastern University has innovatively proposed a closed-loop teaching model： "Construction Supports Competitions-Competitions Nurture Teaching-Teaching Promotes Learning"， aiming at the problem of difficult barrier between scientific research and pedagogy in talent development. This model is based on the requirements for cultivating top innovative talents， leveraging the practical feedback of disciplinary competitions， and creating a dynamic feedback mechanism of "Competition Incubation→Teaching Transformation→Competency Feedback". Taking the award-winning project "Micro-Plasma Emission Spectrometer Setup and Trace Element Analysis Experiment" from the Chemistry Innovation Design Competition as an example， this study demonstrates the model's breakthrough in traditional experimental teaching. Through a 4-class-hour experimental course， students independently construct a dielectric barrier discharge （DBD） micro atomic emission spectroscopy device， combined with hydride generation （HG） introduction technology to complete trace arsenic detection. The method showed a good linear relationship in the mass concentration range of 20-500 μg/L， with a coefficient of determination （R2） of 0.997. Teaching practice shows that students deepened their understanding of principles and made the instrument structure transparent through hands-on construction， promoting the improvement of teaching quality and providing a scalable innovative paradigm for the "high-order， innovative， and challenging" curriculum reform.

Accurate detection and screening of Pb in biological samples is helpful to assess the risk associated with lead pollution to human health. However, conventional atomic spectroscopic instruments are bulky and cumbersome, requiring additional sample pretreatment equipment, and difficult to perform field analysis with. Herein, a portable point discharge (PD) microplasma-optical emission spectrometric (OES) device with online digestion function is designed for field and sensitive determination of lead in biological samples. With rice as a model, online digestion of a batch of six 50 mg samples can be achieved in the HNO3 and H2O2 system within 25 min by a temperature control and timing module. Compared to the conventional microwave digestion, the digestion efficiency of this device reaches 97%. Pb in digestion solution is converted into volatile species by hydride generation (HG) and directly introduced into PD-OES for excitation and detection by a self-designed rotatable and telescopic cutoff gas sampling column. Six samples can be successively detected in 2 min, and argon consumption of the whole process is only <800 mL. Under the optimized conditions, the detection limit of Pb is 0.018 mg kg-1 (0.9 μg L-1) and precision is 3.6%. The accuracy and practicability of the present device are verified by measuring several certified reference materials and real biological samples. By virtue of small size (23.5 × 17 × 8.5 cm3), lightweight (2.5 kg), and low energy consumption (24.3 W), the present device provides a convenient tool for field analysis of toxic elements in biological samples.

Timely diagnosis, monitoring, and management of chronic wounds play crucial roles in improving patients' quality of life, but clinical evaluation of chronic wounds is still ambiguous and relies heavily on the experience of clinician, resulting in increased social and financial burden and delay of optimal treatment. During the different stages of the healing process, specific and dynamic changes of pH values in the wound exudate can be used as biomarkers to reflect the wound status. Herein, a pH-responsive agent with well-behaved photoacoustic (PA) properties, nitrazine yellow (NY), was incorporated in poly(vinyl alcohol)/sucrose (PVA/Suc) hydrogel to construct a wearable pH-sensing patch (PVA/Suc/NY hydrogel) for monitoring of pH values during chronic wound healing. According to Rosencwaig-Gersho theory and the combination of 3D printing technology, the PA chamber volume and chopping frequency were systematically optimized to improve the sensitivity of the PA analytical system. The prepared PVA/Suc/NY hydrogel patch had excellent mechanical properties and flexibility and could maintain conformal contact with skin. Moreover, combined with the miniaturized PA analytical device, it had the potential to detect pH values (5.0-9.0) free from the color interference of blood and therapeutic drugs, which provides a valuable strategy for wound pH value monitoring by PA quantitation. This strategy of combining the wearable hydrogel patch with portable PA analysis offers broad new prospects for the treatment and management of chronic wounds due to its features of simple operation, time savings, and anti-interference.

Microplastics (MPs) can act as carriers of environmental arsenic species into the stomach with food and release arsenic species during digestion, which threatens human health. Herein, an integrated dynamic stomach model (DSM)-capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICPMS) is developed for online monitoring of the release and transformation behaviors of arsenic species loaded on MPs (As-MPs) in the simulated human stomach. The 3D-printed DSM with a soft stomach chamber enables the behaviors of gastric peristalsis, gastric and salivary fluid addition, pH adjustment, and gastric emptying (GE) to be controlled by a self-written program after oral ingestion of food with As-MPs. The gastric extract during digestion is introduced into the spiral channel to remove the large particulate impurity and online filtered to obtain the clarified arsenic-containing solution for subsequent speciation analysis of arsenic by CE-ICPMS. The digestion conditions and pretreatment processes of DSM are tracked and validated, and the release rates of As-MPs digested by DSM are compared with those digested by the static stomach model and DSM without GE. The release rate of inorganic arsenic on MPs is higher than that of organic arsenic throughout the gastric digestion process, and 8% of As(V) is reduced to As(III). The detection limits for As(III), DMA, MMA, and As(V) are 0.5-0.9 mu g L-1 using DSM-CE-ICPMS, along with precisions of <= 8%. This present method provides an integrated and convenient tool for evaluating the release and transformation of As-MPs during human gastric digestion and provides a reference for exploring the interactions between MPs and metals/metalloids in the human body.

Speciation analysis of arsenic in urine is essential for the studies of arsenic metabolism and biological effects, but the unstable arsenic species represented by MMAIII and DMAIII pose a huge challenge to analytical accuracy. Herein, a novel urine self-sampling (USS) kit combined with an automated preparation-sampler (APS) device is rationally designed and used for convenient analysis of arsenic metabolites by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS). The subject can collect urine into a sampling vial at home and use a homemade syringe to pump argon to displace oxygen in the vial, thereby inhibiting the oxidation of MMAIII and DMAIII. After USS and transportation, the sampling vial is loaded directly onto the APS device, where the urine sample can be automatically mixed with diluent, filtered, and loaded into HPLC-ICPMS for arsenic speciation analysis under anaerobic conditions. For a single sample, the sampling time and the analysis time are <8 and <18 min, respectively. The recoveries of MMAIII and DMAIII in urine over 24 h at 4 °C are 86 and 67%, surpassing the conventional sampling method by 28 and 67%, respectively. When the APS is coupled to HPLC-ICPMS, the detection limits of AsC, iAsIII, MMAIII, DMAV, MMAV, DMAIII, and iAsV are 0.03-0.10 μg L-1 with precisions of <10%. The present method provides a convenient and reliable tool for the storage and analysis of unstable arsenic species in urine and lays the foundation for studying the metabolic and biological effects of methylated trivalent arsenicals.

Dried blood spot (DBS) detection has the advantages of small blood collection, convenience, and reliability, which provides a possibility for large-scale evaluation of arsenic exposure in human population. Herein, a facile Lego-spinner pretreatment device is rationally designed for speciation analysis of arsenic in DBSs by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). In the mixing mode of the Lego-spinner, the magnetic stir bar in the centrifuge tube rotates under a magnetic field to assist the dispersive extraction of arsenic species in the DBS with reagents. In the centrifugation mode of the Lego-spinner, the arsenic extract is separated from the blood matrix for the subsequent IC-ICP-MS analysis. For the DBS prepared from 80 μL of whole blood, the whole pretreatment operation can be completed within 25 min. The detection limits of arsenobetaine, arsenite, dimethylarsenate, monomethylarsonate, and arsenate in the DBS are 0.09-0.15 μg L-1, and precisions are <11%. The concentrations of these five arsenic species are highly correlated between whole blood and the DBS (r2 > 0.97), and Bland-Altman analysis indicates that the concentration difference of arsenic species between whole blood and the DBS is within ±20%. The DBS sampling approach can effectively preserve arsenic species for at least 30 days at 4 °C, and the contents of arsenic species in the DBS prepared from capillary blood are in a reasonable agreement with those of venous whole blood (gold standard). This Lego-spinner provides a handy and efficient tool for fast extraction of arsenic species in DBSs, facilitating the in-depth study of arsenic migration and transformation in the human body.

The sliding wear behaviors of three typical stainless steels with various microstructural characteristics, including 2205 duplex stainless steel (2205 DSS), 304 austenite stainless steel (304 ASS), and 430 ferritic stainless steel (430 FSS), are investigated at 20 and −120 °C to address wear failure under cryogenic environment conditions for applications such as spacecraft, polar exploration ships, and liquefied gas storage units. Results show that the wear resistance at 20 °C primarily depends on the initial hardness and strain hardening capacity, whereas toughness becomes increasingly important at −120 °C. The wear resistance of 2205 DSS is slightly higher than that of 304 ASS at 20 °C but much higher than that of 430 FSS. As the temperature decreases to −120 °C, the wear resistances of both 2205 DSS and 304 ASS improve due to the enhanced hardness and favorable toughness endowed by fine grains and the stimulated transformation‐induced plasticity (TRIP) effect, respectively. In contrast, owing to the significant decrease in the toughness of 430 FSS, the worn surface delaminates and the wear resistance deteriorates. Therefore, the effect of toughness on the wear process is not negligible. This study provides guidance for the selection of wear‐resistant materials for different service temperatures.

Speciation analysis of arsenic in blood is essential for identifying and quantifying the exposure of arsenic and studying the metabolism and toxicity of arsenic. Herein, a novel pretreatment device is rationally designed and used for speciation analysis of arsenic in whole blood by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). The sample centrifuge tubes containing blood, reagents, and a magnetic stir bar are placed on the fidget spinner of the pretreatment device. When flicking the fidget spinner rotation with the finger, the magnetic stir bar in the tube rotates in three dimensions under the magnetic field, thereby assisting dispersive extraction of arsenic species by the mixing of blood with reagents. Afterward, the arsenic extract is separated in situ from the blood matrix using an ultrasonic spray sheet covered with a filter and ultrafiltration membrane, which is directly used for subsequent IC-ICP-MS analysis. For 100 μL of blood, the whole pretreatment operation can be completed within 10 min. With As(III), As(V), MMA, and DMA in blood as analytes, the use of the present pretreatment device will hardly lead to the loss and transformation of arsenic species, and the extraction efficiency of the total arsenic is more than 96%. When the pretreatment device is coupled to IC-ICP-MS, the detection limits of four arsenic species in whole blood are 0.017-0.023 μg L-1, and precisions are within 2.3-4.2%. This pretreatment device provides a simple, fast, efficient, and low-cost tool for extraction and separation of arsenic species in whole blood, opening a new idea for the pretreatment of complex samples.

A hierarchical and hybridized hydrogel with rational structure and composition as adsorbent possesses a series of distinct advantages, e.g., fast ion diffusion, high selectivity and good stability. Herein, a novel three-dimensional (3D) molybdenum disulfide (MoS2)-reduced graphene oxide (rGO) hydrogel with two-dimensional heterointerfaces is fabricated by an eco-friendly one-pot hydrothermal method. The heterointerfacial area could be readily tuned by the regulation of MoS2/rGO ratio, in order to improve the adsorption capacity and selectivity. The 3D MoS2-rGO hydrogel with 70 wt% MoS2 shows high selectivity for Hg(II) ions, with a distribution coefficient value (K-d) of 7.49 x 10(6) mL g(-1) even in the presence of other coexisting ions. More attractively, the free-standing and flexible 3D MoS2-rGO hydrogel can be used as a column-packed device, providing an efficient pathway for the fast removal of 80 mg L-1 Hg(II) within 7 min to achieve a tolerable concentration of < 2 mu g L-1 in 30 mL water with 5 mg of 3D MoS2-rGO hydrogel. Considering that the direct-contact adsorption is more efficient than oscillating adsorption, the 3D MoS2-rGO hydrogel as nanobuilding block shows a promising potential for cleaning the point-of-use water. (C) 2017 Elsevier Inc. All rights reserved.

A Pd-free activation pretreatment process was developed for electroless Ni-P plating on NiFe2O4 particles. The main influencing factors, including NiCl2·6H2O concentration, pH of electroless bath and temperature, were investigated. Microstructures of the coating layers were characterized by scanning electron microscopy. It was found that a more uniform and compact Ni-P coating layer was successfully formed by electroless plating via Pd-free activation pretreatment than Pd as sited plating. The coating layers plated by Pd-free activation pretreatment were thicker than those by the sensitization and activation pretreatment on average (9 vs. 5 μm). The new process did not need conventional sensitization or activation pretreatments, because the Ni particles dispersed uniformly on the NiFe2O4 substrate became catalytic activation sites for nickel electroless plating. Such improvement was beneficial to shortening the preparation process and reducing the production costs with the use of noble metal Pd.

NiFe2O4 ceramic inert anode for aluminum electrolysis, strengthened by adding NiFe2O4nanopowder, was preparedvia powder metallurgy method. The effects of NiFe2O4 nanopowder content on sintering behavior and properties of NiFe2O4 ceramic inert anode were studied. Linear shrinkage and scanning electron microscope (SEM) were employed to characterize the sintering property and microstructure. The results show that the sintering shrinkage degree increases gradually as increase of NiFe2O4 nanopowder content, while the sintering temperature and apparent activation energy of initial stage of sintering decrease. When nanopowder content is 40%, the sharp sintering shrinkage begins from 900℃ and the apparent activation energy of initial stage of sintering drops to 291.43 kJ/mol. Volume density, bending strength and fracture toughness are enhanced firstly and then decreased with the increase of nanopowder content, while the porosity and static corrosion rate display opposite tendency. The maximum value of fracture toughness is 3.12 MPa?m1/2 with nanopowder content of 30%, which is 2.14 times that of without adding nanopowder. The toughening effect is realized by the elevated fracture surface energy, which is attributed to the enhanced grain boundary cohesive bond and the reduced porosity with addition of NiFe2O4 nanopowder.

NiFe2O4 ceramic inert anode for aluminum electrolysis, strengthened by adding NiFe2O4 nanopowder, was prepared via powder metallurgy method. The effects of NiFe2O4 nanopowder content on sintering behavior and properties of NiFe2O4 ceramic inert anode were studied. Linear shrinkage and scanning electron microscope (SEM) were employed to characterize the sintering property and microstructure. The results show that the sintering shrinkage degree increases gradually as increase of NiFe2O4 nanopowder content, while the sintering temperature and apparent activation energy of initial stage of sintering decrease. When nanopowder content is 40%, the sharp sintering shrinkage begins from 900 degrees C and the apparent activation energy of initial stage of sintering drops to 291.43 kJ/mol. Volume density, bending strength and fracture toughness are enhanced firstly and then decreased with the increase of nanopowder content, while the porosity and static corrosion rate display opposite tendency. The maximum value of fracture toughness is 3.12 MPa.m(1/2) with nanopowder content of 30%, which is 2.14 times that of without adding nanopowder. The toughening effect is realized by the elevated fracture surface energy, which is attributed to the enhanced grain boundary cohesive bond and the reduced porosity with addition of NiFe2O4 nanopowder.