Construction and Application of Nanozyme Sensor Arrays.

Compared with traditional "lock-key mode" biosensors, a sensor array consists of a series of sensing elements based on intermolecular interactions (typically hydrogen bonds, van der Waals forces, and electrostatic interactions). At the same time, sensor arrays also have the advantages of fast response, high sensitivity, low energy consumption, low cost, rich output signals, and imageability, which have attracted widespread attention from researchers. Nanozymes are nanomaterials which own enzyme-like properties. Because of the adjustable activity, high stability, and cost effectiveness of nanozymes, they are potential candidates for construction of sensor arrays to output different signals from analytes through the chemoresponse of colorants, which solves the shortcomings of traditional sensors that they cannot support multiple detection and lack universality. Recently, a sensor array based on nanozymes as nonspecific recognition receptors has attracted much more attention from researchers and has been applied to precise recognition of proteins, bacteria, and heavy metals. In this perspective, attention is given to nanozymes and the regulation of their enzyme-like activity. Particularly, the building principles and methods for sensor arrays based on nanozymes are analyzed, and the applications are summarized. Finally, the approaches to overcome the challenges and perspectives are also presented and analyzed for facilitating further research and development of nanozyme sensor arrays. This perspective should be helpful for gaining insight into research ideas within the field of nanozyme sensor arrays.

Screening indicators to evaluate the clinical significance of drug-drug interactions in polypharmacy among older adults with psychiatric disorders: a delphi study.

BACKGROUND: Polypharmacy is common in older adults with psychiatric disorders, but no consensus has reached about the reliable indicators evaluating the benefits and risks of drug-drug interactions (DDIs) in polypharmacy. We aimed to identify indicators suitable for evaluating the clinical significance of DDIs in polypharmacy in older adults with psychiatric disorders. METHODS: The online tools were used to distribute and collect the questionnaires. The Delphi method was applied to analyze experts' opinions. The degree of authority and coordination of experts were analyzed using the coefficient of variation, coefficient of coordination, expert's judgment factor, familiarity with the study content factor, and Kendall coordination coefficient. Statistical analysis was conducted using the IBM SPSS® Statistics Package version 26.0. RESULTS: After three rounds of expert consultation, five primary and eleven secondary indicators were identified. The primary "pharmacodynamic indicator" included "severity of adverse drug reactions", "duration of adverse drug reaction", "symptom relief", "time to onset of symptomatic relief", "number of days in hospital", and "duration of medication". The secondary "pharmacokinetic indicator" contained "dosage administered" and "dosing intervals". The primary "patient tolerance indicator" contained one secondary indicator of "patient tolerability". The primary indicator "patient adherence" contained one secondary indicator of "patient adherence to medication". The primary indicator "cost of drug combination" contained one secondary indicator of "readmission". These indicators were used to determine the clinical significance of DDIs during polypharmacy. CONCLUSIONS: The clinical significance of drug combinations should be taken into account when polypharmacy is used in the elderly. The five primary indicators and eleven secondary indicators might be preferred to evaluate their risks and benefits. Medication management in this population requires a multidisciplinary team, in which nurses play a key role. Future research should focus on how to establish efficient multidisciplinary team workflows and use functional factors to assess DDIs in polypharmacy for psychiatric disorders.

Effects of telehealth interventions on the caregiver burden and mental health for caregivers of people with dementia: a systematic review and meta-analysis.

OBJECTIVES: To systematically evaluate the effects of telehealth interventions on the caregiver burden and mental health of caregivers for people with dementia (PWD). METHOD: Relevant randomized controlled trials (RCTs) of telehealth interventions on caregivers were extracted from nine electronic databases (PubMed, The Cochrane Library, Web of Science, Embase, CINAHL, SinoMed, CNKI, WanFang, and VIP). The retrieval time was from inception to 26 July 2023. RESULTS: Twenty-two articles with 2132 subjects were included in the final analysis. The meta-analysis demonstrated that telehealth interventions exerted a significant effect in reducing caregiver burden (SMD: -0.14, 95 % CI: -0.25, -0.02, p = 0.02), depression (SMD = -0.17; 95%CI: -0.27, -0.07, p < 0.001) and stress (SMD = -0.20, 95%CI: -0.37, -0.04, p = 0.01). However, no statistically significant effect was observed on anxiety (SMD = -0.12, 95%CI: -0.27, 0.03, p = 0.12). Moreover, subgroup analysis showed that tailored interventions were associated with more evident reductions in depression (SMD = -0.26; 95%CI: -0.40, -0.13, p < 0.001) than standardized interventions (SMD = -0.08; 95%CI: -0.22, 0.06, p = 0.25). In addition, telehealth was effective in relieving depression in Internet-based (SMD = -0.17, 95%CI: -0.30, -0.03, p = 0.01) and Telephone-based group (SMD = -0.18, 95%CI: -0.34, -0.02, p = 0.03), while there was no significant difference in the Internet and Telephone-based group (SMD = -0.18, 95%CI: -0.54, 0.18, p = 0.32). CONCLUSION: Telehealth could effectively reduce the burden and relieve the depression and stress of caregivers of PWD, while its effect on anxiety requires further research. Overall, telehealth has potential benefits in dementia care.

Staff's experiences of a culturally specific DEmentia Competence Education for Nursing home Taskforce (DECENT) programme: A qualitative process evaluation.

AIM: To understand participants' experiences with a culturally specific DEmentia Competence Education for Nursing home Taskforce programme within the contexts which was delivered. DESIGN: An exploratory descriptive qualitative approach. METHODS: Semi-structured individual interviews were conducted within one week with the participants upon their completion of the programme from July 2020 to January 2021. A purposive sample of participants with different demographic characteristics in five nursing homes was recruited to maximize the sample variation. Interviews were audiotaped and transcribed verbatim for qualitative content analysis. Participation was on voluntary and anonymous basis. RESULTS: Four major themes were identified, including perceived benefits of the programme (i.e., enhanced sensitivity to the needs of residents with dementia, increased communication with families of residents with dementia, facilitated guidance on care for residents with dementia), facilitators (i.e., comprehensive content, active learning, qualified trainer, intrinsic motivation and organizational support), barriers (i.e., busy working schedules, discrimination against care assistants' learning capability) and suggestions for improvement. CONCLUSION: The results suggested the acceptability of the programme. The participants positively appraised the programme in enhancing their dementia-care competence. The facilitators, barriers and suggestions identified provide insights on improving programme implementation. IMPACT: The qualitative findings from the process evaluation are pertinent to support the sustainability of dementia competence programme in nursing home setting. Future studies could address the modifiable barriers to enhance its effectiveness. REPORTING METHOD: This study was reported in adherence to the Consolidated criteria for reporting qualitatve studies (COREQ) checklist. PATIENT AND PUBLIC CONTRIBUTION: Nursing-home staff was involved in intervention development and delivery. IMPLICATIONS FOR PRACTICE/POLICY: The educational programme could be integrated into the routine practice in nursing homes to improve staff's dementia-care competence. More attention should be paid on the educational needs of the taskforce when implementing the educational programme in nursing homes. Organizational support is the precondition for the educational programme and cultivates a culture for practice change.

A new three-dimensional (3D) molecularly imprinted polymer fluoroprobe based on green-red dual-emission signals of carbon quantum dots and self-polymerization of dopamine (CDs@PDA-MIPs) for sensitive detection of nifedipine.

Nifedipine (NIF), as one of the dihydropyridine calcium channel blockers, is widely used in the treatment of hypertension. However, misuse or ingestion of NIF can result in serious health issues such as myocardial infarction, arrhythmia, stroke, and even death. It is essential to design a reliable and sensitive detection method to monitor NIF. In this work, an innovative molecularly imprinted polymer dual-emission fluorescent sensor (CDs@PDA-MIPs) strategy was successfully designed for sensitive detection of NIF. The fluorescent intensity of the probe decreased with increasing NIF concentration, showing a satisfactory linear relationship within the range 1.0 × 10-6 M ~ 5.0 × 10-3 M. The LOD of NIF was 9.38 × 10-7 M (S/N = 3) in fluorescence detection. The application of the CDs@PDA-MIPs in actual samples such as urine and Qiangli Dingxuan tablets has been verified, with recovery ranging from 97.8 to 102.8% for NIF. Therefore, the fluorescent probe demonstrates great potential as a sensing system for detecting NIF.

The effectiveness of chin-down manoeuvre in patients with dysphagia: A systematic review and meta-analysis.

AIM: The chin-down posture is a widely used compensatory manoeuvre for patients with dysphagia. The aim of this study was designed to systematically measure the effectiveness of chin-down manoeuvre application. METHODOLOGY: We retrieved the PubMed, Web of Science, Embase, Cochrane Library, EBSCO, Medline, CNKI, WANFANG, VIP and SinoMed databases from inception to 30 August 2022. Raters independently screened literature according to inclusion and exclusion criteria. The quality of the included literature was evaluated, and data were extracted. The software Review Manager software 5.3 was used for statistical analysis. RESULTS: Fourteen studies with a total of 571 patients were included in this meta-analysis. The meta-analysis indicated that chin-down manoeuvre could significantly reduce the risk of aspiration (MD = -1.35, 95% CI [-2.25, -0.44], Z = 2.92, p < .01), decrease the chin angle (MD = -12.20, 95% CI [-14.61, -9.79], Z = 9.91, p < .001), shorten oral transit time (MD = -0.81, 95% CI [-1.20, -0.43], Z = 4.17, p < .001), reduce the maximum swallowing pressure at upper oesophageal sphincter (MD = -82.07, 95% CI [-112.77, -51.37], Z = 5.24, p < .001) and decrease pharyngeal residue. CONCLUSIONS: Existing evidence indicated that chin-down manoeuvre could reduce the risk of aspiration and pharyngeal residue, decrease the maximum swallowing pressure at UES. More large-sample, high-quality clinical trials are still needed in the future to further ascertain the results of this research.

A multi-stakeholder collaboration model of dementia-friendly communities: Experiences from Nanjing, China.

The care for people with dementia (PwD) in low- and middle-income countries (LMICs) is dominated by home care and supplemented sporadically by public care provided using public resources. In the context of community resources cannot meet the demand for high-quality services for PwD, dementia-friendly communities (DFCs) provide ideas for alleviating this situation by integrating resources from multiple stakeholders. However, there is still a considerable gap between the capacity of services and the demand of PwD. Based on the experience of elderly services and DFCs construction in Nanjing, China, this study developed a stakeholder collaboration model and clarified the collaborative relationship among stakeholders such as the government, communities, and medical institutions in meeting the needs of PwD. This work summarizes the partnerships and specific actions of stakeholders and highlights the importance of facilitating resource integration to provide comprehensive services.

Research Progress in Iron-Based Nanozymes: Catalytic Mechanisms, Classification, and Biomedical Applications.

Natural enzymes are crucial in biological systems and widely used in biology and medicine, but their disadvantages, such as insufficient stability and high-cost, have limited their wide application. Since Fe3O4 nanoparticles were found to show peroxidase-like activity, researchers have designed and developed a growing number of nanozymes that mimic the activity of natural enzymes. Nanozymes can compensate for the defects of natural enzymes and show higher stability with lower cost. Iron, a nontoxic and low-cost transition metal, has been used to synthesize a variety of iron-based nanozymes with unique structural and physicochemical properties to obtain different enzymes mimicking catalytic properties. In this perspective, catalytic mechanisms, activity modulation, and their recent research progress in sensing, tumor therapy, and antibacterial and anti-inflammatory applications are systematically presented. The challenges and perspectives on the development of iron-based nanozymes are also analyzed and discussed.

An Advanced Molecularly Imprinted Photochemical Sensor Based Carbon Quantum dots for Highly Sensitive Detection of Chloramphenicol in Food.

A facile method which combines the advantages of carbon quantum dots and molecular imprinting technology to design a fluorescence molecular imprinting sensor for the high sensitivity and selective detection of chloramphenicol. The fluorescent molecule imprinted polymers are synthesized by sol-gel polymerization using carbon quantum dots as functional monomers and fluorescent sources, TEOS as crosslinkers, breaking with the traditional understanding of an additional functional monomer. Under optimal experimental, as the concentration of chloramphenicol increases, the fluorescence intensity of the fluorescence molecule imprinting sensor gradually decreases. The concentration of chloramphenicol is linear in the range of 5-100 µg/L and the detection limit is 1 µg/L (N/S = 3). The sensor is able to detect chloramphenicol in milk, enabling the application of real samples. The results show that this work provides an easy method to preparing fluorescent molecular imprinting sensors for the detection of chloramphenicol in milk.

Multimorbidity patterns and the association with health status of the oldest-old in long-term care facilities in China: a two-step analysis.

BACKGROUND: The increasing prevalence of multimorbidity has created a serious global public health problem in aging populations. Certain multimorbidity patterns across different age ranges and their association with health status remain unclear. The main aim of this study is to identify multimorbidity patterns discrepancies and associated health status between younger-old and oldest-old. METHODS: The Ethics Committee of Nanjing Medical University approved the study protocol (No.2019-473). Convenience sampling method was used to recruit older adults aged ≥ 60 years with multimorbidity from July to December 2021 from 38 Landsea long-term care facilities in China. The multimorbidity patterns were analyzed using network analysis and two-step cluster analysis. One-Way ANOVA was utilized to explore their association with health status including body function, activity of daily living, and social participation. A Sankey diagram visualized the flow of health status within different multimorbidity patterns. This study is reported following the STROBE guidelines. RESULTS: A total of 214 younger-old (60-84 years) and 173 oldest-old (≥ 85 years) were included. Leading coexisting diseases were cardiovascular disease (CD), metabolic and endocrine disease (MED), neurological disease (ND), and orthopedic disease (OD). Cluster 1 (53, 24.8%) of CD-ND (50, 94.3%; 31, 58.8%), cluster 2 (39, 18.2%) of MED-ND-CD (39, 100%; 39, 100%; 37, 94.9%), cluster 3 (37, 17.3%) of OD-CD-MED-ND (37, 100%; 33, 89.2%; 27, 73.0%; 16, 43.2%), and cluster 4 (34, 15.9%) of CD-MED (34, 100%; 34, 100%) were identified in the younger-old. In the oldest-old, the primary multimorbidity patterns were: cluster 1 (33, 19.1%) of CD-respiratory disease-digestive disease-urogenital disease (CD-RD-DSD-UD) (32, 97.0%; 9, 27.3%; 8, 24.2%; 7, 21.2%), cluster 2 (42, 24.3%) of ND-CD-MED (42, 100%; 35, 83.3%; 14, 33.3%), cluster 3 (28, 16.2%) of OD-CD-MED (28, 100%; 25, 89.3%; 18, 64.3%), and cluster 4 (35, 20.2%) of CD-MED (35, 100%; 35, 100%). Younger-old with CD-ND or MED-ND-CD, and oldest-old with ND-CD-MED have worse health status compared with other multimorbidity patterns (e.g., CD-MED and OD-CD-MED). CONCLUSION: Discrepancies in common patterns of multimorbidity across age groups suggest that caregivers in long-term care facilities should consider changes in multimorbidity patterns with ageing when developing prevention plans for individualized management. Neurological disease concurrent with other diseases was the major determinant of health status, especially for the oldest-old. Interventions targeting multimorbidity need to be focused, yet generic. It is essential to assess complex needs and health outcomes that arise from different multimorbidity patterns and manage them through an interdisciplinary approach and consider their priorities to gain high-quality primary care for older adults living in long-term care facilities.

Longitudinal relationships between grip strength, subjective memory complaints and cognitive function among middle-aged and older adults in China.

BACKGROUND: Subjective memory complaints are considered an early sign of cognitive decline. Recent evidence shows that grip strength is an important predictor of cognitive function. However, few studies have compared whether one condition is uniquely associated with cognitive function when another condition is controlled for. AIMS: To explore the longitudinal associations of cognitive function with subjective memory complaints and grip strength in middle-aged and older adults, with a particular focus on whether one condition is uniquely associated with cognitive function when another condition is considered. METHODS: A total of 3,877 middle-aged and older adults (aged 45-92 years) from the China Health and Retirement Longitudinal Study reported on their demographic and health status and completed measures of grip strength and subjective memory complaints, as well as a series of cognitive tests, every two years between 2011 and 2015. Generalized estimating equation models were used to assess the relationships between grip strength, subjective memory complaints, and cognitive function. RESULTS: Grip strength was longitudinally associated with cognitive function (ß = 0.021, 95% confidence interval [CI]: 0.011, 0.030, P < 0.001) independent of subjective memory complaints. In contrast, changes in the subjective memory complaints were not related to cognitive function over time (ß = 0.107, 95% CI: - 0.025, 0.238, P = 0.112). Only at baseline subjective memory complaints were associated with poorer cognitive function (ß = - 1.142, 95% CI: - 1.309, - 0.975, P < 0.001). CONCLUSIONS: Grip strength might be a more important clinical correlate of cognitive function decline over time than subjective memory complaints. DISCUSSION: Regular assessment and close monitoring of grip strength might help identify individuals who might be at high risk for cognitive impairment.

A molecularly imprinted electrochemical sensor with dual functional monomers for selective determination of gatifloxacin.

A molecularly imprinted electrochemical sensor was designed for the selective determination of gatifloxacin (GTX) based on dual functional monomers. Multi-walled carbon nanotube (MWCNT) enhanced the current intensity and zeolitic imidazolate framework 8 (ZIF8) provided a large surface area to produce more imprinted cavities. In the electropolymerization of molecularly imprinted polymer (MIP), p-aminobenzoic acid (p-ABA) and nicotinamide (NA) were used as dual functional monomers, and GTX was the template molecule. Taking [Fe(CN)6]3-/4- as an electrochemical probe, an oxidation peak on the glassy carbon electrode was located at about 0.16 V (vs. saturated calomel electrode). Due to the diverse interactions among p-ABA, NA, and GTX, the MIP-dual sensor exhibited higher specificity towards GTX than MIP-p-ABA and MIP-NA sensors. The sensor had a wide linear range from 1.00 × 10-14 to 1.00 × 10-7 M with a low detection limit of 2.61 × 10-15 M. Satisfactory recovery between 96.5 and 105% with relative standard deviation from 2.4 to 3.7% in real water samples evidenced the potential of the method in antibiotic contaminant determination.

Association between career adaptability and turnover intention among nursing assistants: the mediating role of psychological capital.

BACKGROUND: High turnover intention of nursing assistants was detrimental to the sustainability of long-term care. Career adaptability is an important determinant in reducing turnover intention, but little research has explored the mechanism from the perspective of psychological capital. The aim of this study was to analyze the association between career adaptability and turnover intention and to examine the mediating role of psychological capital between career adaptability and turnover intention among nursing assistants in mainland China. METHODS: A cross-sectional online study was conducted among 276 nursing assistants from eight nursing homes in Nanjing, China. The participants' career adaptability, psychological capital, and turnover intention were obtained. SPSS 26.0 and Amos 24.0 software were employed for statistical analysis. RESULTS: Career adaptability was positively related to psychological capital and negatively linked to turnover intention (P < 0.01). Psychological capital played a fully mediating role (ß = -0.085, P < 0.05) in the relationship between career adaptability and turnover intention, and the largest indirect effect was generated through the curiosity dimension. CONCLUSIONS: The management of long-term care facilities should focus on assessing the level of career adaptability of nursing assistants. The overall improvement of career adaptability and psychological capital is conducive in reducing turnover intention. Targeted interventions are recommended to improve career adaptability and reduce turnover intentions by increasing career curiosity. Online career adaptability programs can be developed for nursing assistant students to improve their psychological capital and facilitate career transitions.

Molecularly imprinted electrochemical aptasensor based on functionalized graphene and nitrogen-doped carbon quantum dots for trace cortisol assay.

This paper proposes a novel electrochemical aptasensor that integrates molecular imprinting techniques for trace analysis of cortisol. This sensor is based on functionalized graphene and nitrogen-doped carbon quantum dots. The morphology and structure of the modified electrode were characterized by scanning electron microscopy and Raman spectroscopy. The functional monomer aptamer and the template molecule cortisol were adsorbed on the electrode by electrostatic adsorption to construct an imprinted sensing platform. Under the optimal conditions, such as the concentration of template molecule, the ratio of template to functional monomer, the elution and adsorption time, the sensor exhibits linearity and a low detection limit of 10-12-10-8 M and 3.3 × 10-13 M, which is more sensitive than other reported cortisol analysis methods. In addition, this sensor can realize the determination of cortisol in salivary samples with high recovery values, showing great development potential in the field of life sciences.

A FRET Fluorescent Sensor for Ratiometric and Visual Detection of Sulfide Based on Carbon Dots and Silver Nanoclusters.

In this work, the fluorescent sensor based on fluorescence resonance energy transfer (FRET) and electrostatic interaction (EI) was prepared for the ratiometric and visual detecting S2-. The FRET fluorescent sensor consists of two fluorophores, with carbon dots (CDs) as energy donors and silver nanoclusters (Ag NCs) as acceptors. At 390 nm excitation, CDs and Ag NCs showed two well-separated peaks at 445 nm and 660 nm, separately. The existence of S2- caused the red fluorescence at 660 nm to be quenched, whereas the blue fluorescence at 445 nm was restored, and the fluorescence color of the ratiometric sensor changed from pink to blue. It could be employed in ratiometric and visual detecting S2-. The linear range of quantitative detection S2- was 0.5-100 µM, and its detection limit was 0.35 µM. CDs-Ag NCs could be used for detecting S2- in mineral water and tap water. The results showed that the FRET ratiometric fluorescent sensor exhibits good anti-interference and high selectivity for detecting S2- in environmental water samples.

A Significant Fluorescent Aptamer Sensor Based on Carbon Dots and Graphene Oxide for Highly Selective Detection of Progesterone.

In this paper, a fluorescent aptamer sensor was constructed based on the carbon dots (CDs) and graphene oxide (GO). This sensor combines the excellent fluorescence performance of CDs with the high specificity of aptamer, which can detect progesterone (P4) with high sensitivity and selectivity. In the absence of P4, the CDs-aptamer system and GO form a fluorescence resonance energy transfer process (FRET), which quenches the fluorescence of the CDs. When P4 is added, the aptamer specifically binds to it, resulting the fluorescence of the CDs is recovered. At optimal conditions, the fluorescence intensity recovered by the CDs has a linear relationship with the concentration of P4 in the range of 0.1-120 nM and the detection limit is 3.3 × 10-11 M. Besides, the sensor has satisfactory detection results of P4 in milk, indicating that constructed method has enormous potential for application in food safety.

Clinical significance of potential drug-drug interactions in older adults with psychiatric disorders: a retrospective study.

BACKGROUND: Polypharmacy increases the risk of potential drug-drug interactions (pDDIs). This retrospective analysis was conducted to detect pDDIs and adverse drug reactions (ADRs) among older adults with psychiatric disorder, and identify pDDIs with clinical significance. METHODS: A retrospective analysis was carried out based on the medical records of older adults with psychiatric disorders. Data on demographic characteristics, substance abuse, medical history, and medications were extracted. The Lexi-Interact online database was used to detect pDDIs. The minimal clinically important difference (MCID) was set as the change in the Treatment Emergent Symptom Scale (TESS) score between admission and discharge. The median and interquartile ranges were used for continuous variables, and frequencies were calculated for dichotomous variables. Poisson regression was implemented to determine the factors influencing the number of ADR types. The influencing factors of each ADR and the clinical significance of the severity of the ADR were analysed using binary logistic regression. P < 0.05 was considered statistically significant. RESULTS: A total of 308 older adults were enrolled, 171 (55.52%) of whom had at least 1 pDDI. Thirty-six types of pDDIs that should be avoided were found, and the most frequent pDDI was the coadministration of lorazepam and olanzapine (55.5%). A total of 26 ADRs induced by pDDIs were identified, and the most common ADR was constipation (26.05%). There was a 9.4 and 10.3% increase in the number of ADR types for each extra medical diagnosis and for each extra drug, respectively. There was a 120% increase in the number of ADR types for older adults hospitalized for 18-28 days compared with those hospitalized for 3-17 days. There was an 11.1% decrease in the number of ADR types for each extra readmission. The length of hospitalization was a risk factor for abnormal liver function (P < 0.05). The use of a large number of drugs was a risk factor for gastric distress (P < 0.05) and dizziness and fainting (P < 0.05). None of the four pDDIs, including coadministrations of olanzapine and lorazepam, quetiapine and potassium chloride, quetiapine and escitalopram, and olanzapine and clonazepam, showed clinical significance of ADR severity (P > 0.05). CONCLUSIONS: pDDIs are prevalent in older adults, and the rate is increasing. However, many pDDIs may have no clinical significance in terms of ADR severity. Further research on assessing pDDIs, and possible measures to prevent serious ADRs induced by DDIs is needed to reduce the clinical significance of pDDIs.

Functional characterization of ABC transporters mediates multiple neonicotinoid resistance in a field population of Aphis gossypii Glover.

The ATP-binding cassette (ABC) transporters C and G subfamilies have been reported to be involved in insecticide detoxification, with most studies showing increased gene transcript levels in response to insecticide exposure. Our previous studies have suggested that ABCC and G transporters participate in cyantraniliprole and thiamethoxam resistance of Aphis gossypii. In this study, we focused on the potential roles of the ABCC and G transporters of an A. gossypii field population (SDR) in neonicotinoid detoxification. The results of leaf dip bioassays showed 629.17- and 346.82-fold greater resistance to thiamethoxam and imidacloprid in the SDR strain, respectively, than in the susceptible strain (SS). Verapamil, an ABC inhibitor, was used for synergism bioassays, and the results showed synergistic effects with thiamethoxam, with synergistic ratios (SRs) of 2.07 and 6.68 in the SS and SDR strains, respectively. In addition to thiamethoxam, verapamil increased imidacloprid toxicity by 1.68- and 1.62-fold in the SS and SDR strains respectively. Then, the expression levels of several ABCC and G transporters were analyzed in different treatments. We found that the transcript levels of AgABCG4, AgABCG17, AgABCG26, AgMRP8 and AgMRP12 were higher in the SDR strain than in the SS strain. The mRNA expression of AgABCG4, AgABCG7, AgABCG13, AgABCG17, AgABCG26, AgMRP8 and AgMRP12 in the SDR strain was increased after thiamethoxam and imidacloprid exposure. The results of transgenic Drosophila melanogaster bioassays suggested that overexpression of AgABCG4, AgABCG7, AgABCG13, AgABCG17, AgABCG26, AgMRP8 and AgMRP12 in transgenic flies was sufficient to confer thiamethoxam and imidacloprid resistance, and AgABCG4, AgABCG7, AgABCG13, AgABCG26 and AgMRP12 may be related to α-cypermethrin cross-resistance with weak effects. In addition, the knockdown of AgABCG4, AgABCG13, AgABCG26, AgMRP8 and AgMRP12, and the knockdown of AgABCG7 and AgABCG26 increased thiamethoxam and imidacloprid mortality in the SDR strain, respectively. Our results suggest that changes in the expression levels of ABCC and G transporters may contribute to neonicotinoid detoxification in the SDR strain, and provide a foundation for clarify the potential roles of ABCC and G transporters in insecticide resistance.

Near-infrared carbon dots for cell imaging and detecting ciprofloxacin by label-free fluorescence sensor based on aptamer.

A label-free fluorescence sensor based on near-infrared carbon dots (NIR-CDs) and aptamer is described for the highly sensitive and selective detection of ciprofloxacin (CIP). NIR-CDs were synthesized from polyethyleneimine and reduced glutathione by one-step hydrothermal method. The electrostatic interaction between the positively charged carbon dots and the negatively charged aptamer resulted in fluorescence quenching. After the addition of CIP, the specific binding between CIP aptamer and CIP was stronger, resulting in fluorescence recovery. Under the optimal experimental conditions, the recovered fluorescence intensity has a linear relationship with the concentration of CIP in the range 0.5-800 ng/mL, and the detection limit is 0.167 ng/mL. The prepared carbon dots have excellent optical properties and biocompatibility, and due to their emission characteristics in the near-infrared window, they can be used for biological imaging, which has also been confirmed in the experiment. The feasibility of the label-free fluorescence sensor for the detection of CIP is also proved by confocal fluorescence imaging. The detection results of CIP determination in milk by this sensor are satisfactory, indicating that the developed sensor has great application potential.

A molecularly imprinted electrochemical aptasensor based on zinc oxide and co-deposited gold nanoparticles/reduced graphene oxide composite for detection of amoxicillin.

The molecularly imprinted electrochemical aptasensor was constructed based on co-deposition of zinc oxide and gold nanoparticles/reduced graphene oxide composite. Aptamer was used as a new kind of functional monomer and the aptamer-amoxicillin complex was formed by hydrogen bond. Then, the complex was fixed on the surface of the modified electrode by Au-S bond. Three-dimensional imprinted polymeric membrane was formed by electropolymerization of dopamine, and the imprinted sites with good specificity and affinity were formed after elution. Combined with the specificity of molecularly imprinted technology and the affinity of aptamer, the selective recognition of amoxicillin can be realized. Under the optimal experimental conditions, the linear range was from 10-14 to 10-8 M, and the detection limit was 3.3 × 10-15 M. The sensor exhibited satisfactory selectivity, repeatability, and stability and was successfully used for 10-9 M amoxicillin determination in real water and food samples.