Terbium alginate encapsulated CsPbI3@Pb-MOF: a ratiometric fluorescent bead for detection and adsorption of Fe3.

Halide perovskite nanocrystals are innovative luminescent materials for fluorescent probes with high quantum yield and narrow emission bandwidth. However, the limited stability, single-signal response, and separation challenges obstruct their widespread use in water ion detection. Herein, a ratiometric fluorescence sensor based on terbium alginate gel beads (green fluorescent, namely Tb-AG) embedded with powdered CsPbI3@Pb-MOF (red fluorescent) was prepared for fluorescent determination and adsorption of Fe3+. Pb-MOF's protection notably enhances the water stability of CsPbI3, while the energy transfer between CsPbI3@Pb-MOF and Tb3+ elevates the optical performance of CsPbI3@Pb-MOF@Tb-AG. Significantly, Fe3+ markedly suppresses CsPbI3@Pb-MOF red fluorescence at 647 nm, while not noticeably affecting Tb-AG green emission at 528 nm. The sensor exhibited a strong linear response to Fe3+ concentrations ranging from 0 to 90 µM, with a detection limit of 0.44 µM and high selectivity. The CsPbI3@Pb-MOF@Tb-AG-based sensor has been effectively validated through its successful use in detecting Fe3+ in tap and river water samples. Furthermore, CsPbI3@Pb-MOF@Tb-AG demonstrates a notable adsorption capacity of 325.4 mg g-1 Fe3+. Finally, the mechanism of Fe3+ detection and adsorption was determined.

The Relationship Between Fear Avoidance Belief and Threat Learning in Postoperative Patients After Lung Surgery: An Observational Study.

Background: The role of fear-avoidance beliefs (FAB) in patients with chronic pain has been widely confirmed. However, few conclusions have been drawn about its role in postoperative patients. Objective: To explore the characteristics of FAB in postoperative patients after lung surgery as well as the effect of threat learning on FAB. Methods: Between May and September 2022, this study recruited 150 participants who had undergone thoracoscopic surgery. Variables such as age, gender, education, chronic pain, fear of pain, surgery method, pain intensity, FAB, cough, ambulation and threat learning were collected and subjected to correlation analysis and stepwise regression. Results: The correlation analysis revealed that FAB was associated with age (r = -0.183, p < 0.05), gender (r = -0.256, p < 0.01), and preoperative FOP-9 (r = 0.400, p < 0.01). Postoperative variables such as pain intensity (r = 0.574, p < 0.01), initiation day of ambulation (r = 0.648, p < 0.01), total numbers of ambulation (r = -0.665, p < 0.01), and cough performance (r = -0.688, p < 0.01) were correlated with FAB. Furthermore, FAB was highly correlated with indicators of threat learning: direct (r = 0.556, p < 0.01), observation (r = 0.655, p < 0.01), and instruction (r = 0.671, p < 0.01). The highest variance explanation model of stepwise regression which explained 52.8% of the variance including instruction (B=1.751; p<0.01), direct (B=1.245; p<0.01), observation (B=0.768; p<0.01), age (B=-0.085; p<0.01), and surgery method (B=1.321; p<0.05). Conclusion: Patients commonly experience FAB after lung surgery, which can directly affect their recovery behaviors such as ambulation and active coughing. The formation of FAB is influenced by threat learning, which suggests that controlling threat learning is important in preventing postoperative FAB.

Fear of Pain as a Predictor for Postoperative Pain Intensity among the Patients Undergoing Thoracoscopic Surgery.

Background: Fear of pain (FOP) has been recognized as an influential moderator and determinant of the perception and disability of chronic pain. However, studies on FOP in postoperative acute pain are few and inconsistent. Objective: To explore whether FOP is related to pain intensity after thoracic surgery and provide a reference for FOP study in postoperative pain. Methods: From February to March 2022, 89 patients completed Chinese Version of Fear of Pain-9 Items (FOP-9), Chinese version of the Brief Pain Inventory (BPI, including least, worst, and average pain) and Simplified Chinese version of the Pain Catastrophizing Scale (PCS). Correlation analyses and mediation analyses were used for exploring the relationship between factors. Results: Mediation analyses showed that the total effects of FOP-9 on BPI all were significant (least pain: effect = 0.085, p=0.013, 95% CI = 0.019∼0.151; worst pain: effect = 0.116, p=0.004, 95% CI = 0.037∼0.196; average pain: effect = 0.102, p=0.005, 95% CI = 0.031∼0.174) indicating that FOP-9 was a predictor to BPI. The 95% bias-corrected bootstrap confidence interval of estimate of indirect effect between FOP-9 and least pain/average pain through PCS was -0.036∼0.024 and -0.003∼0.069 (all contain zero), which indicated that PCS is not a mediator between FOP-9 and least pain/average pain. However, the estimate of indirect effect between FOP-9 and worst pain through PCS were 0.048 (95% CI = 0.095∼0.088), and direct effect was not statistically significant (95% CI = -0.017∼0.153), indicating that PCS acted as a complete intermediary between FOP-9 and worst pain. FOP-9 and PCS showed significant positive prediction effect on worst pain. Conclusions: Both trait FOP and state FOP were associated with higher postoperative pain reports after thoracic surgery. Trait FOP influences postoperative pain through the mediating effect of state FOP.

Study on simplified strategies for procedure of rapid detection of water toxicity.

In this work, a simplified procedure of detection of water toxicity based on Pt ultramicroelectrode (UME) and mixed microorganism cultured without sterilization was the first proposed. A stable Pt UME was successfully prepared with a special glass tube as insulation and support material, which was used as working electrode in the biosensor. The Pt UME exhibits the typical cyclic voltammogram (CV) of Pt UME with sigmoid shape and possesses good stability, enlarged current response and tunable dimension. In addition, it was an effective and simple method for toxicity biosensor using mixed microorganisms cultured in unsterilized lysogeny broth (LB) as the bioreceptor. K3[Fe(CN)6] was used as an electron mediator. Under the optimal conditions of 30 mM K3[Fe(CN)6], OD600 = 1 cell concentration, and 50 mM phosphate-buffered solution (PBS), the half-maximal inhibitory concentration (IC50) values measured for Cd2+, Cu2+ and Ni2+ were 3.99 mg/L, 1.16 mg/L and 2.37 mg/L, respectively. The results indicated that the biosensor with large diameter Pt UME and mixed microorganisms cultured in unsterilized LB realized rapid and simple detection of water toxicity.

Translation and Validation of Fear of Pain-9 Items into Simplified Chinese Version for Mainland China.

PURPOSE: This study aimed to obtain a translation and validation of the Fear of Pain Questionnaire 9 Items (FOP-9) into simplified Chinese. METHODS: The questionnaire was translated following the forward-backward method. The final version was filled out by (n = 300) patients. Cronbach's coefficient was calculated to test the internal consistency of simplified Chinese version of FOP-9 (sc-FOP-9), and 50 painless patients completed the sc-FOP-9 questionnaire within a 2-weeks interval to evaluate test-retest reliability. To verify the construct validity, exploratory factor analysis was used to explore the factor structure, and confirmatory factor analysis was conducted to evaluate the goodness fit of models. RESULTS: Satisfactory psychometric qualities were obtained (Cronbach's α of the total score was 0.873 and intraclass correlation coefficient was 0.975). Three first-order models were tested and all show a good model fit and the 3-factor structure may be better due to its higher factor loading. CONCLUSION: The sc-FOP-9 is a reliable and valid instrument to evaluate the fear of pain among Chinese patients with or without pain. Fear of pain may have an important effect on perioperative pain and chronic pain, and this tool is a good complement to the measurement in mainland China.

Fabrication of a Novel, Cost-Effective Double-Sided Indium Tin Oxide-Based Nanoribbon Electrode and Its Application of Acute Toxicity Detection in Water.

Microelectrode plays a crucial role in developing a rapid biosensor for detecting toxicity in water. In this study, a nanoribbon electrode (NRE) with amplified microelectrode signal was successfully prepared by electrodepositing 2-allylphenol on a double-sided indium tin oxide glass. The NRE provided a simple mean for obtaining large steady-state current response. Its advantages were discussed by contrasting the toxicity detection of 3,5-dichlorophenol (DCP) with single microelectrode, microelectrode array, and millimeter electrode as working electrodes in which potassium ferricyanide (K3[Fe(CN)6]) was adopted as a mediator, and Escherichia coli was selected as bioreceptor. At a constant potential of 450 mV, the current reached a steady state within 10 s. The biosensor was constructed using the NRE as working electrode, and its feasibility was verified by determining the toxicity of DCP. A 50% inhibitory concentration (IC50) of 3.01 mg/L was obtained by analyzing the current responses of different concentrations of DCP within 1 h. These results exhibited that the proposed method based on the as-prepared NRE was a rapid, sensitive, and cost-effective way for toxicity detection in water.

A comparison study of test organism species and methodologies for combined toxicity assay of copper ions and zinc ions.

The general toxicity assays for evaluating the risk of aquatic environment were commonly based on single-species test organism models. Thus, the lack and conflict of the different responses among species had hindered researchers to assess the real toxicity of a target toxicant. Therefore, the difference between the test species and their corresponding methodologies was investigated in this work and three species, Escherichia coli, Saccharomyces cerevisiae and Misgurnus anguillicaudatus (a fish), were chosen as the test organism for typical prokaryotes, eukaryotes, and vertebrates, respectively. More specifically, we investigated (i) the individual and combined toxicity of Cu2+ and Zn2+ by the three test organisms; (ii) the different evaluation manners for the test organisms, including IC50 and toxic unit (TU) model for microorganisms by respiratory toxicity assay and enzyme-substrate assay, while survival time for fish; and (iii) the states of test organism, including suspended and immobilized states for microorganisms. The combined effects, including synergistic (Vt < Vp), antagonistic (Vt > Vp) and additive effects for the three species, were complex as that they were usually dose-dependent and could be changed by the different evaluation manners. The present work was useful for enriching of the associated theory and the insights from this work could open the way for further practical risk assessments.

An unexpected discovery of 1,4-benzoquinone as a lipophilic mediator for toxicity detection in water.

Since most toxicological risk assessments are based on individual single-species tests, there is uncertainty in extrapolating these results to ecosystem assessments. Herein, we successfully developed a mediated microbial electrochemical biosensor with mixed microorganisms for toxicity detection by microelectrode array (MEA). In order to fully mobilize all the mixed microorganisms to participate in electron transfer to amplify the current signal, 1,4-benzoquinone (BQ) was used as the lipophilic mediator to mediate the intracellular metabolic activities. Hydrophilic K3[Fe(CN)6] was employed as an extracellular electron acceptor to transport electrons from hydroquinone (HQ) to the working electrode. Under the optimal conditions of 50 mM phosphate buffer solution (PBS), 0.4 mM BQ, 10 mM K3[Fe(CN)6] and OD600 = 0.5 bacteria concentration, the half-maximal inhibitory concentration (IC50) values measured with the composite-mediated respiration (CM-RES) of BQ-K3[Fe(CN)6] for Cu2+, Cd2+ and Zn2+ were 5.95, 7.12 and 8.86 mg L-1, respectively. IC50 values obtained with the single mediator K3[Fe(CN)6] were 2.34, 5.88 and 2.42 mg L-1 for the same samples. The results indicate that the biosensor with the single mediator K3[Fe(CN)6] had higher sensitivity to heavy metal ions than the biosensor with composite mediators. After verification, we found that the addition of BQ cannot amplify the current. The IC50 value of 0.89 mg L-1 for BQ was obtained using K3[Fe(CN)6] as the single mediator. This suggests that BQ is highly toxic, which explained why the sensitivity of the biosensor with the combined mediator BQ-K3[Fe(CN)6] was lower than that of the biosensor with the single mediator K3[Fe(CN)6]. At the same time, this also implies that toxicity itself cannot be ignored when it is used as an electronic mediator in a mediated microbial electrochemical biosensor.

Investigation on the stress response of microbes in acute toxicity assay.

Acute toxicity assay by using microbes as bioindicators is an effective tool for reflecting the impact of water pollution on organisms. Until now, the suspended state of microbes is still mainly adopted, because the immobilized state of microbes will cause the poor stability of toxicity assay due to the microbes being reused. Here, an electrochemical biosensor based on biofilm was established for toxicity assay (TOX-biosensor), and the stress response of immobilized microbes in biofilm was demonstrated as the main factor that resulting in instability of the TOX-biosensor, and it can be induced by both of dose and time accumulation. The intensity of stress response for measuring a toxicant absence of organic substance was triple of that presence, indicating extracellular substances can be used for microbial repair and result in the decrease of the consumption of endogenous substance. Herein, a weak magnetic field (WMF) was employed to balance the activity of biofilm in the present TOX-biosensor, and a low intensity of WMF 10 GS was demonstrated to have the function for weakening stress response. Under this condition, the signals of biosensor can be kept stable for a month and the recovery time of dormant TOX-biosensor can be shorted from 50 h to 10 h. Its mechanism may be associated with the special magnetic field inside the organisms and the charge transfer happened in the life activity process.

A respiration substrate-less isolation method for acute toxicity assessment.

Respiration substrate (RS)-less isolation method was developed for enhancing the sensitivity of acute toxicity assessment of heavy metal ions. RS was removed from the first step of previous isolation method, which was an effective strategy for improving acute toxicity assessment. 50% inhibiting concentration (IC50) values of Cu2+, Cd2+, Zn2+, Hg2+ and Ni2+ were 0.39 mg L-1, 5.99 mg L-1, 3.99 mg L-1, 0.23 mg L-1 and 5.74 mg L-1, respectively. Beyond that, the complicacy of organic toxicants assessments was investigated by choosing 3,5-dichlorophenol (DCP) as model toxicant. Biofilm sensor, morphology method and suspended microbes-based methods including one-pot method, RS-isolation method, RS-less isolation method, RS-less isolation method with added potassium ferricyanide (+F), were compared. The sensitivity to DCP can be ranked as morphology method > suspended microbes-based methods > biofilm method. The difference of the present results implicated that the methodological interference, leading in different detection mechanisms of these methods. The relative investigations can provide theoretical guidance for developing comprehensive detection methods of pollutants.

How to Identify the "LIVE/DEAD" States of Microbes Related to Biosensing.

In this work, we fabricated a microbial biosensor with long-term stability, which relied on microbial activity. Activity of the microbe was commonly estimated by LIVE/DEAD assay and the propidium iodide (PI)-stained one was judged as dead. Herein, we proposed the utilization of a physiological state of microbes, which was neither live nor dead but between them. In this state, microbes represented a high PI-stained ratio but still had catalytic ability. This microbial state was obtained by forming the biofilm under the conditions of poor nutrition and low temperature. Thus, the dividing and proliferating ability of the microbes in the biofilm was weak, which was beneficial for long-term stability. This mechanism was further confirmed by the biosensors made from multifarious substrate materials, including graphene-based gel, biomass-based gel, graphite felt, and poly(vinyl chloride). This biosensor was applied to water pollution monitoring in the laboratory for 2 years and then was integrated into a multiparameter water quality monitoring station on a local lake for 2.5 years.