Formation Mechanisms, Interrelationships, and Effects of Cognitive Factors on Diet and Physical Activity During the Post-Bariatric Surgery Period: A Cross-Sectional Study Based on Compensatory Carry-Over Action Model.

Background: Diet and physical activity (PA) are pivotal behaviors for managing energy balance post-bariatric surgery. Given the need for dual behavioral management, understanding the interplay of cognitive factors influencing these behaviors is crucial. This study applied the compensatory carry-over action model (CCAM) to explore the impact of cognitive factors on behaviors and their subsequent effects on subjective health outcomes. Methods: This cross-sectional study was conducted among patients at the third month after bariatric surgery in China. Data on diet and PA status, behavioral cognitive factors (intention, self-efficacy, compensatory belief, transfer cognition), and subjective health outcomes (perceived stress, well-being, quality of life) were collected. Structural equation model (SEM) was employed to test hypotheses in CCAM and assess mediation relationships. Results: Analysis of data from 239 patients revealed the following: (1) Among antecedent cognitive factors, only compensatory belief significantly influenced diet (P<0.001). (2) Intention and self-efficacy directly correlated with their respective behaviors, while compensatory belief affected intention, and transfer cognition impacted self-efficacy (P<0.05), aligning with CCAM hypotheses. (3) PA demonstrated significant influence only on perceived stress (P=0.004), whereas diet significantly affected all subjective health outcomes (P<0.05). (4) Mediation analysis indicated intention partially mediated the relationship between compensatory belief and diet and fully mediated the relationship between compensatory belief and PA. Self-efficacy completely mediated the relationship between transfer cognition and diet and PA. Conclusion: Transfer cognition's carry-over effect did not directly influence behaviors among antecedent cognitions. Interventions should primarily target improving diet by mitigating compensatory belief. Moreover, diet exhibited a more pronounced impact on overall health compared to PA. Consequently, prioritizing dietary intervention over PA intervention is warranted based on the analysis of CCAM and the aim of promoting joint behaviors post-bariatric surgery.

Individual, family and social-related factors of eating behavior among Chinese children with overweight or obesity from the perspective of family system.

Purpose: The purpose of the present study is to examine the factors contributing to the development of eating behavior in overweight and obese children from the perspective of the family system. Methods: A cross-sectional survey was conducted by using convenience sampling method to select 388 participants in two primary schools in Jiangsu, China. Individual, family and social-related factors were collected. Individual factors included age, gender, ethnicity, single child, social anxiety, depression, physical activity, sleep duration, screen time. Family factors included family environment, family structure, family function, family income, parenting style, parental feeding behavior, home food environment and marital satisfaction. Social-related factors included place of residence, number of surrounding restaurants and social support. Univariate analysis, correlation analysis and multivariate analysis were used to identify factors of eating behavior among Chinese children with overweight and obese. Results: In this study, 388 participants took part with a 94.865% response rate. In the univariate analysis, the significant differences regarding Dutch Eating Behavior Questionnaire (DEBQ) scores were found between children aged 6-9 years and those aged >9 years. Correlation analysis indicated that parent's nutrition literacy (r = 0.118, P < 0.05), pressure to eat (r = 0.212, P < 0.01), perception of child weight (r = -0.112, P < 0.05) and family function (r = -0.563, P < 0.01) were associated with children's eating behavior. With regard to psychosocial factors, children's social anxiety (r = 0.299, P < 0.01) and depressive symptoms (r = 0.081, P < 0.05) were in positive correlation with eating behavior. The independent variables included in the initial model were age, father's employment status, social anxiety, maternal punishment and harshness, parents' nutrition literacy, pressure to eat, family function and perception of child weight. These variables in the final model accounted for 20.7% of the variance. Conclusion: We found that age, father's employment status, social anxiety, maternal punishment and harshness, parents' nutrition literacy, pressure to eat, family function and perception of child weight have great effect on children's eating behavior who are overweight or obese. As early childhood is a critical timeline for child development, children's social anxiety, parenting style, parent's nutrition literacy, parent's feeding behavior and family function should be intervened to promote eating behavior. Intervention programs aimed at promoting healthy eating behaviors among children, thereby mitigating the risk of pediatric obesity, should primarily target parents.

Balancing "on" and "off" response of hydroxyl groups to a nanozyme-catalyzing system for the construction of an ultra-sensitive and selective "signal-on" detection platform for dopamine.

Targeting the functional groups present in analytes by nanozyme-catalyzed systems is a promising strategy to construct sensitive and selective platforms for the sensing of specific analytes. Herein, various groups (-COOH, -CHO, -OH, and -NH2) on benzene were introduced in an Fe-based nanozyme system with MoS2-MIL-101(Fe) as the model peroxidase nanozyme, H2O2 as the oxidizing agent, and TMB as the chromogenic substrate, and the effects of these groups at both a low concentration and high concentration were further investigated. It was found that the hydroxyl group-based substance catechol showed an "on" effect at a low concentration to increase the catalytic rate and enhance the absorbance signal, whereas an "off" effect at a high concentration with a decreased absorbance signal. Based on these results, the "on" mode and "off" mode for the biological molecule dopamine, a type of catechol derivative, were proposed. In the control system, MoS2-MIL-101(Fe) catalyzed the decomposition of H2O2 to produce ROS, which further oxidized TMB. In the "on" mode, the hydroxyl groups of dopamine could combine with the Fe(iii) site of the nanozyme to lower its oxidation state, resulting in higher catalytic activity. In the "off" mode, the excess dopamine could consume ROS, which inhibited the catalytic process. Under the optimal conditions, by balancing the "on" and "off" modes, the "on" mode for the detection of dopamine was found to have better sensitivity and selectivity. The LOD was as low as 0.5 nM. This detection platform was successfully applied for the detection of dopamine in human serum with satisfactory recovery. Our results can pave the way for the design of nanozyme sensing systems with sensitivity and selectivity.

Recovery of vanadium with melamine in acidic medium.

Many hydro-metallurgical methods are developed to recover vanadium, while ammonium salt precipitation possesses the final step and it has threatened the environment. The key point is to find a new compound to replace ammonium salts without reducing vanadium recovery efficiency. Some compounds with -NH2 function groups have attracted our attention as they have similar function groups with ammonium salts. In this paper, the adsorption of vanadium with melamine is conducted. The results show that high adsorption efficiency can be achieved in a short time and melamine displays great performance in the recovery of all concentrations of vanadium. Response surface methodology (RSM) is used to optimize the reaction conditions and order the parameters: reaction temperature > concentration of vanadium > dosage of melamine > reaction time. 99.63% vanadium is adsorbed under optimized conditions: n(melamine)/n(V) = 0.6, reaction time of 60 min, 10 g/L vanadium solution and reaction temperature of 60°C. The successful application of melamine in the recovery of vanadium provides a new way for the utilization of melamine and also a glorious future for -NH2 compounds in the recovery heavy metals.

Atomically dispersed Fe/Bi dual active sites single-atom nanozymes for cascade catalysis and peroxymonosulfate activation to degrade dyes.

Constructing single-atom nanozymes (SAzymes) with densely exposed and dispersed double metal-Nx catalytic sites for pollution remediation remains rare and challenging. Herein, we report a novel Fe-Bi bimetallic MOF-derived carbon supported Fe-N4 and Bi-N4 dual-site FeBi-NC SAzyme for cascade catalysis and peroxymonosulfate activation to degrade dye pollutants, which is synthesized from the Fe-doped Bi-MOF as a precursor. The formation of both Fe-N4 and Bi-N4 sites is demonstrated by XANES and EXAFS. The FeBi-NC SAzyme has high single atoms loadings of Fe (2.61 wt%) and Bi (8.01 wt%), and displays 5.9- and 9.8-fold oxidase mimicking activity enhancement relative to the Fe-NC and Bi-NC SAzymes, respectively. When integrated acetylcholinesterase (AChE) and FeBi-NC SAzyme, a cascade enzyme-nanozyme system is developed for selective and sensitive screening of AChE activity with a low detection limit of 1 × 10-4 mU mL-1. Both Fe-N4 and Bi-N4 in FeBi-NC display a strong binding energy and electron donating capability to promote peroxymonosulfate activation to generate highly active intermediates for rhodamine B degradation. 100% rhodamine B removal occurs within 5 min via FeBi-NC mediated activation of peroxymonosulfate. The DFT calculations reveal that high activity of FeBi-NC is due to the isolated Fe-N4 and Bi-N4 sites and their synergy.

Recent advances in catalytic hairpin assembly signal amplification-based sensing strategies for microRNA detection.

Accumulative evidences have indicated that abnormal expression of microRNAs (miRNAs) is closely associated with many health disorders, making them be regarded as potentialbiomarkers for early clinical diagnosis. Therefore, it is extremely necessary to develop a highly sensitive, specific and reliable approach for miRNA analysis. Catalytic hairpin assembly (CHA) signal amplification is an enzyme-free toehold-mediated strand displacement method, exhibiting significant potential in improving the sensitivity of miRNA detection strategies. In this review, we first describe the potential of miRNAs as disease biomarkers and therapeutics, and summarize the latest advances in CHA signal amplification-based sensing strategies for miRNA monitoring. We describe the characteristics and mechanism of CHA signal amplification and classify the CHA-based miRNA sensing strategies into several categories based on the "signal conversion substance", including fluorophores, enzymes, nanomaterials, and nucleotide sequences. Sensing performance, limit of detection, merits and disadvantages of these miRNA sensing strategies are discussed. Moreover, the current challenges and prospects are also presented.

Structural Engineering of Hollow Microflower-like CuS@C Hybrids as Versatile Electrochemical Sensing Platform for Highly Sensitive Hydrogen Peroxide and Hydrazine Detection.

Designing metal sulfides with unique configurations and exploring their electrochemical activities for hydrogen peroxide (H2O2) and hydrazine (N2H4) is challenging and desirable for various fields. Herein, hollow microflower-like CuS@C hybrids were successfully assembled and further exploited as a versatile electrochemical sensing platform for H2O2 reduction and N2H4 oxidation, of which the elaborate strategies make the perfect formation of hollow architecture, providing considerable electrocatalytic sites and fast charge transfer rate, while the appropriate introduction polydopamine-derived carbon skeleton facilitates the electronic conductivity and boosts structural robustness, thus generating wide linear range (0.05-14 and 0.01-10 mM), low detection limit (0.22 µM and 0.07 µM), and a rather low overpotential (-0.15 and -0.05 V) toward H2O2 and N2H4, as well as good selectivity, excellent reproducibility, and admirable long-term stability. It should be highlighted that the operating potentials can compare favorably with those of some reported H2O2 and N2H4 sensors based on noble metals. In addition, good recoveries and acceptable relative standard deviations (RSDs) attained in serum and water samples fully verify the accuracy and anti-interference capability of our proposed sensor systems. These results not only elucidate an effective structural nanoengineering strategy for electroanalytical science but also advance the rational utilization of H2O2 and N2H4 in practicability.

Hierarchical Brookite TiO2-Bi2MoO6 Nanospheres with Efficient Visible-Light-Driven Photocatalytic Response.

Hierarchical TiO2-Bi2MoO6 nanospheres as efficient visible-light responsive photocatalyst are fabricated by dispersing brookite TiO2 nanorods on the hierarchical Bi2MoO6 nanospheres, which provides visible-light absorption and large surface area. The morphologies, surface area and light absorption features of as-prepared TiO²-Bi²MoO6 can be rational controlled by varying the loading amount of TiO² nanorods on hierarchical Bi²MoO6 nanospheres. As a result, the TiO²-Bi²MoO6-3 yields 380 ppm CO² production for decomposing 2-propanol at 11 h under visible light irradiation, realizing 4.4 times enhancement of photocatalytic property with respect to pure TiO² nanorods. Moreover, the three-dimensional hierarchical architecture enables the hybrid TiO²-Bi²MoO6 excellent cycling stability.

Facile and rapid synthesis of emission color-tunable molybdenum oxide quantum dots as a versatile probe for fluorescence imaging and environmental monitoring.

Recent years have seen molybdenum oxide quantum dots (MoOx QDs) as a booming material due to their attractive physical and chemical properties. However, there is still a large demand for MoOx QDs with long-wavelength emission by a facile strategy but these are more challenging to obtain. Herein, we rationally designed and successfully prepared nitrogen and phosphorus co-doped green emitting MoOx QDs (N,P-MoOx QDs) through a microwave-assisted rapid method. They exhibit a maximum emission at 500 nm under a 430 nm excitation. Moreover, by controlling their sizes in the process, we find that such a strategy enables the tuning of the emission color of N,P-MoOx QDs from green to blue. N,P-MoOx QDs show a significant fluorescence response to pH changes, and also display pH-sensitive near-infrared localized surface plasmon resonance (LSPR) at 866 nm. An effective and simple pH probe with a dual-signal response is achieved using N,P-MoOx QDs. As environmental sensors, N,P-MoOx QDs can be applied for sensitive detection of the concentrations of permanganate and captopril, offering the linear range from 0.08 to 25 µM and 0.1 to 31 µM, respectively. Benefitting from the effect of doping nitrogen and phosphorus, the probe could detect a wide range of pH changes (2-9) and is endowed with superior biocompatibility. Further, it is successfully used to "see" the intracellular pH variation by fluorescence confocal imaging. These findings not only demonstrate the achievement of a promising multifunctional probe for biosensing and environmental detection, but also pave the way for the fabrication of transition metal oxide QDs with tunable optical properties.

"Signal-on" SERS sensing platform for highly sensitive and selective Pb2+ detection based on catalytic hairpin assembly.

In this work, a surface-enhanced Raman scattering (SERS) sensing strategy was proposed for the analysis of lead ion (Pb2+) with high sensitivity and specificity based on the high specificity of the catalytic nucleic acids (DNAzymes) to Pb2+ and the catalytic hairpin assembly (CHA) amplification. First, the Pb2+-DNAzyme initiated the reaction by target Pb2+ and released a linear DNA (rS1). Second, the hairpin DNA 1 (H1) was immobilized on the SERS substrate surface via Ag-S bond. Then, the rS1 could cyclically trigger the allosteric effects of CHA amplification and the H1 was opened and then the R6G-labeled hairpin probe 2 (H2) hybridized with H1 to form H1-H2 double-stranded and the released rS1 could initiate the next cycle of CHA reaction. This process made the Raman tag of R6G close to the surface of SERS substrate, and the intensity of SERS signal from R6G labels increase with the increase of concentration of target Pb2+. Benefiting from outstanding performances of the Pb2+-specific DNAzymes and enzyme-free CHA amplification system, this biosensor exhibits good sensitivity for Pb2+ with a limit of detection of 0.42 pM. More importantly, this developed detection platform could be employed for reliable analysis of Pb2+ in real environment system.

Coordination-driven assembly of a 3d-4f heterometallic organic framework with 1D Cu4I4 and Eu-based chains: syntheses, structures and various properties.

A three-dimensional porous 3d-4f heterometallic organic framework, namely, {[Eu3(Cu4I4)3(INA)9(DMF)4]·3DMF}n (YNU-2), was successfully prepared under solvothermal conditions. There are two different one-dimensional metal chains in the structure, namely, Cu4I4 and EuIII-based chains, resulting in an excellent stability of the prepared sample. A N2 sorption isotherm at 77 K revealed that the activated sample exhibits a Brunauer-Emmett-Teller surface area of 371 m2 g-1, while, YNU-2 can adsorb obviously higher CO2 amounts than CH4 at 273 K and 298 K under 1 atm because of the stronger interaction force between CO2 and the porous skeleton. Furthermore, YNU-2 is highly efficient heterogeneous catalyst for chemical fixation of the CO2 and epoxides into cyclic carbonates with a preferable recyclability. Taking into account its excellent stability, the prepared sample can be used to construct an electrochemical adapter sensor for detecting cocaine with a detection limit of 0.27 pg mL-1 in the wide range of 0.001-0.5 ng mL-1.

High-Efficiency CNNS@NH2-MIL(Fe) Electrochemiluminescence Emitters Coupled with Ti3C2 Nanosheets as a Matrix for a Highly Sensitive Cardiac Troponin I Assay.

Synthesis of a highly efficient electrochemiluminescence (ECL) luminescent material is one of the effective means to improve the sensitivity of the sensor. In this study, an efficient ECL luminescent nanomaterial, carbon nitride nanosheet (CNNS) decorated amino-functional metal-organic frameworks (CNNS@NH2-MIL(Fe)) were synthesized for sensitive ECL detection of cardiac troponin I (cTn-I). The synthesized CNNS@NH2-MIL(Fe) realized the effective mass loading of CNNS, and more importantly, the NH2-MIL(Fe) could expedite the reduction of coreactant S2O82- to produce abundant ECL reaction intermediate SO4•- near CNNS, thus, shortening the distance between SO4•- and the excited state of CNNS with less energy loss to extremely enhance the ECL signal of CNNS. Furthermore, the ECL signal of the immunosensor could be further enhanced when the Ti3C2 nanosheet was used as the matrix to capture primary anti-cTn-I due to the reason that Ti3C2 not only exhibited a large surface area and excellent metallic conductivity, but also could act as a coreaction accelerator to speed up the reduction of S2O82- with plenty of SO4•- generated. Therefore, this proposed ECL immunosensor using CNNS@NH2-MIL(Fe) as a signal probe and Ti3C2 as a sensing matrix exhibited a significantly enhanced ECL signal and had a high sensitivity and excellent selectivity for cTn-I. Consequently, this multiple signal amplification strategy provided an effective method for trace protein ultrasensitive detection in ECL bioanalysis.

Assembly of Two Self-Interpenetrating Metal-Organic Frameworks Based on a Trigonal Ligand: Syntheses, Crystal Structures, and Properties.

Two self-interpenetrating metal-organic frameworks (MOFs) 1 and 2 were designed and constructed through the coordination self-assembly of transition metal nodes and a trigonal ligand. They both exhibit interesting three-dimensional constructions with the 1 + 2 self-locked mode. Because of the outstanding moisture susceptibility and luminescence property, MOF 1 has a potential detectability toward nitrofurantoin (NFT) in water. More importantly, MOF 1 can efficiently monitor NFT in bovine serum. Taking into account of Lewis basic sites in the skeleton, MOF 2 can be implemented as an outstanding heterogeneous catalyst for the Knoevenagel reaction. Furthermore, they both reveal excellent circularity and an application effect for five cycles.

Rational design and synthesis of a stable pillar-layer NaI-organic framework as a multi-responsive luminescent sensor in aqueous solutions.

A stable pillar-layer NaI-organic framework, [Na2(DCPB)∙(H2O)2]n (namely 1), was rationally designed and synthesized by the assemble process of NaI and 1,3-di(4'-carboxyl-phenyl)benzene (H2DCPB). Benefiting from the luminescent property and high stability in water, the as-synthesized 1 is a potential multi-responsive luminescent sensor material toward Cr2O72-, Fe3+, and nitrofurazone (NFZ) in water. Ground 1 not only has the excellent detectability and selectivity but also possesses outstanding stability and circularity. The calculated Ksv values of 1 are 8.8×103 for Fe3+, 9.9×103 for Cr2O72-, and 2.7×104 M-1 for NFZ in aqueous solutions, respectively. Furthermore, 1 is able to accurately detect NFZ in real bovine serum samples through luminescence detection technology.

Lengthening the aptamer to hybridize with a stem-loop DNA assistant probe for the electrochemical detection of kanamycin with improved sensitivity.

By adding 6 thymines to lengthen the parent aptamer combined with the change of "on" and "off" induced by the target for an assistant stem-loop DNA probe (ASP-SLP-MB), a new folding-type electrochemical kanamycin (Kana) aptamer-engineering dual-probe-based sensor (sensor d) was developed. By purposefully reducing the background current and increasing the electron transfer efficiency of methylene blue (MB), the sensor obtained significantly enhanced detection sensitivity compared with non-aptamer-engineering one-probe-based sensor (sensor a). Such efficacy was validated by a big decrease from 530.6 to 210.2 nA for the background current signal and from 360 to 0.3 nM for the detection limit. In addition to the improved sensitivity, the sensor also exhibited good selectivity, anti-fouling detection performance, and potential quantitative analysis ability, showing a feasible potential practical analytical application in real-life complicated samples, for example, milk and serum. The released results prove that the aptamer-engineering method is effective in improving the analytical performance of folding-type sensors and provides a methodological guidance for the design and fabrication of other high-performance folding-type aptasensors. Graphical abstract.

A simple enzyme-free SERS sensor for the rapid and sensitive detection of hydrogen peroxide in food.

A simple enzyme-free method based on surface-enhanced Raman scattering (SERS) was developed for the first time to detect H2O2 in food by etching a self-assembled film of silver nanoparticles (Ag NPs) on a glass substrate. H2O2 is able to oxidize Ag NPs to yield Ag+ ions; this process reduces the size of the Ag NPs and ultimately leads to a decrease in the SERS signal of the Raman probe. The intensities of the SERS spectra were strongly correlated with H2O2 concentration, which indicated that the Ag NP self-assembled SERS sensor can be successfully used for the quantitative analysis of H2O2. The main advantage of this SERS sensor is that it can directly detect H2O2 without introducing complex enzymatic reactions. This easy-to-operate and fast-response detection technology has great potential for the sensitive detection of H2O2 in food.

Copper-Catalyzed Coupling of Sulfonamides with Alkylamines: Synthesis of (E)-N-Sulfonylformamidines.

Herein, we describe an efficient copper-catalyzed coupling of sulfonamides with alkylamines to synthesize (E)-N-sulfonylformamidines. The reaction is accomplished under mild conditions without the use of a corrosive acid or base as an additive. It tolerates a broad scope of substrates and generates the products with exclusive (E)-stereoselectivity.

Ratiometric SERS biosensor for sensitive and reproducible detection of microRNA based on mismatched catalytic hairpin assembly.

MicroRNAs (miRNAs) serve as significant regulators in a variety of diseases and have been emerging as a class of promising biomarkers for early cancer diagnosis. Herein, an enzyme-free surface-enhanced Raman scattering (SERS) platform was proposed for sensitive and reliable detection of target miRNA-21 using a corrective internal standard (IS)-based ratiometric SERS probe coupled with mismatched catalytic hairpin assembly (CHA) amplification. The 4-aminothiophenol (4-ATP) was used as IS molecule and modified on the surface of silver nanoparticles decorated silicon wafer. In principle, the presence of miRNA-21 could cyclically trigger the allosteric effects of mismatched CHA amplification and the 3'-R6G labeled hairpin probe 1 (H1) was opened. Then, the hairpin probe 2 (H2) hybridized with H1 to form H1-H2 complex and the released miRNA-21 was free to participate in the next cycle of CHA reaction. Meanwhile, the H1-H2 complex could hybridize with the capture DNA on the SERS chip, making the Raman tag of R6G close to the surface of SERS substrate, and the intensity of SERS signal from R6G labels increase while that from 4-ATP remain relatively unchanged. Benefiting from outstanding performances of the ratiometric SERS strategy and enzyme-free CHA amplification system, this platform exhibits sensitivity toward miRNA-21 with a limit of detection of 3.5 fM and a broad dynamic range from 10 fM to 100 nM. More importantly, this proposed method presents an excellent reliable SERS analysis with the correction of IS. The developed strategy holds a potential alternative tool for miRNA detection in biomedical research and early clinical diagnosis.

An excellently stable TbIII-organic framework with outstanding stability as a rapid, reversible, and multi-responsive luminescent sensor in water.

An excellently stable TbIII-organic framework, [TbL·2H2O]n (complex 1), has been successfully synthesized through an assembly process. By virtue of its excellent water stability and strong green luminescence, complex 1 has been considered and applied as a reversible multi-responsive luminescent sensor for Fe3+, Cr2O72-, and nitrofurantoin (NFT) aqueous solutions. Complex 1 not only exhibits outstanding detection effects with high selectivity and sensitivity, but also shows remarkable cycling and regeneration abilities. The Ksv values of complex 1 for Fe3+, Cr2O72-, and NFT are 2.27 × 104, 2.31 × 104, and 5.26 × 104 M-1 in water systems, respectively. More importantly, complex 1 can accurately monitor NFT in real bovine serum samples via luminescence quenching detection.