Developing a psychological care competences framework for nurses in China: a mixed methods study.

BACKGROUND: With social transformation, rapid economic development and deepening awareness of psychological health in China, people's demand for psychological health services is becoming increasingly urgent. A key challenge for Chinese medical organizations is to train enough qualified psychological care nurses. A greater understanding of psychological care competences (PCC) can help in clinical nurse selection, training, and assessment. OBJECTIVE: To develop a PCC framework for Chinese nurses and obtain a consensus on the framework among experts. METHODS: A descriptive mixed methods study was designed consisting of a literature review and semi-structured interviews followed by three Delphi rounds. The experts (n = 16) involved were nurses, nursing managers and educators from nine Chinese provinces with a specific interest in psychological care. Descriptive statistics assisted in data analysis. RESULTS: Using the Iceberg Model as a theoretical foundation, five main dimensions and associated subdomains were integrated from 39 chosen articles. The semi-structured interviews with 24 nursing managers and nurses confirmed all of the themes from the literature review while generating new themes, both of which were incorporated into the initial PCC framework. After three Delphi rounds, the experts reached consensus on the PCC framework, including five domains (knowledge, skills, professional ethics, personal traits, internal motivations) and 22 subdomains with connotations. The response rate (RR) values for the three rounds of consultation were 80.00%, 87.50% and 92.86%, the composite reliability (Cr) values were 0.89-0.90, and the Kendall coordination coefficients were 0.155-0.200 (P < 0.05). CONCLUSIONS: On the basis of the Iceberg Model, literature review and qualitative research methods along with Delphi technique were used to develop a scientific and systematic PCC framework. The research methods were feasible and the results were reliable, thereby providing a basis for adopting this framework into nursing education. A formal assessment tool should be developed to test the PCC of nurses in clinical practice.

Photothermal Conversion Perylene-Based Metal-Organic Framework with Panchromatic Absorption Bandwidth across the Visible to Near-Infrared.

Recently, facilely designable metal-organic frameworks have gained attention in the construction of photothermal conversion materials. Nonetheless, most of the previously reported photothermal conversion metal-organic frameworks exhibit limited light absorption capabilities. In this work, a distinctive metal-organic framework with heterogeneous periodic alternate spatial arrangements of metal-oxygen clusters and perylene-based derivative molecules was prepared by in situ synthesis. The building blocks in this inimitable structure behave as both electron donors and electron acceptors, giving rise to the significant inherent charge transfer in this crystalline material, resulting in a narrow band gap with excellent panchromatic absorption, with the ground state being the charge transfer state. Moreover, it can retain excellent air-, photo-, and water-stability in the solid state. The excellent stability and broad light absorption characteristics enable the effective realization of near-infrared (NIR) photothermal conversion, including infrequent NIR-II photothermal conversion, in this perylene-based metal-organic framework.

Differential Characteristics of Fatigue-Pain-Sleep Disturbance-Depression Symptom Cluster and Influencing Factors of Patients With Advanced Cancer During Treatment: A Latent Class Analysis.

BACKGROUND: Patients with advanced cancer may experience symptom clusters during treatment (eg, fatigue, pain, sleep disturbance, depression). Understanding the characteristics and factors associated with symptom cluster classes among this patient population is essential for effective symptom management. OBJECTIVE: The aims of this study were to identify symptom cluster (fatigue-pain-sleep disturbance-depression) classes and explore influencing factors in patients with advanced cancer during the treatment. METHODS: A cross-sectional survey was conducted in an oncology department of a tertiary hospital in China from September 2020 to March 2021. Cancer patients (stage III/IV) 18 years or older completed the questionnaires on pain, fatigue, sleep disturbance, depression, physical activity, and exercise self-efficacy. Latent class analysis and multinomial logistic regression were used. RESULTS: Three hundred sixty-five patients who were male (65.2%) and younger than 60 years (59.5%) completed questionnaires. Three symptom cluster classes were identified: class 1 ("low symptom burden" class), class 2 ("fatigue-insomnia" class), and class 3 ("high symptom burden" class), with a percentage of 54.5%, 38.6%, and 6.8%, respectively. The quality-of-life score, introversion/extroversion, economic burden, Karnofsky Performance Status, albumin level, and exercise self-efficacy were significantly different among the 3 classes (P < .05). CONCLUSION: Patients with advanced cancer were classified into 3 distinct classes, with class 1 having the best function. Results from this study reveal that Karnofsky Performance Status, albumin level, and exercise self-efficacy were significant factors for the latent classes of symptom cluster. IMPLICATIONS FOR PRACTICE: Exercise self-efficacy is important for personalized interventions and improving symptom management efficiency.

Thermodynamically and Kinetically Stabilized Pt Clusters Against Sintering on CeO2 Nanofibers Through Enclosing CeO2 Nanocubes.

Sintering is a major concern for the deactivation of supported metals catalysts, which is driven by the force of decreasing the total surface energy of the entire catalytic system. In this work, a double-confinement strategy is demonstrated to stabilize 2.6 nm-Pt clusters against sintering on electrospun CeO2 nanofibers decorated by CeO2 nanocubes (m-CeO2 ). Thermodynamically, with the aid of CeO2 -nanocubes, the intrinsically irregular surface of polycrystalline CeO2 nanofibers becomes smooth, offering adjacent Pt clusters with decreased chemical potential differences on a relatively uniform surface. Kinetically, the Pt clusters are physically restricted on each facet of CeO2 nanocubes in a nanosized region. In situ high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) observation reveals that the Pt clusters can be stabilized up to 800 °C even in a high density, which is far beyond their Tammann temperature, without observable size growth or migration. Such a sinter-resistant catalytic system is endowed with boosted catalytic activity toward both the hydrogenation of p-nitrophenol after being aged at 500 °C and the sinter-promoting exothermic oxidation reactions (e.g., soot oxidation) at high temperatures over 700 °C. This work offers new opportunities for exploring sinter-resistant nanocatalysts, starting from the rational design of whole catalytic system in terms of thermodynamic and kinetic aspects.

Astrocytic purinergic signalling contributes to the development and maintenance of neuropathic pain via modulation of glutamate release.

Although activation of astrocytes is critical in developing neuropathic pain (NP) following nerve injury, the underlying mechanisms of NP and therapeutic management for NP are still vague. Importantly, the decreases in the levels of astrocytic glutamate transporter-1 (GLT-1) in the spinal dorsal horn result in enhanced excitatory transmission and cause persistent pain. P2Y1 purinergic receptor (P2Y1R) has been shown to enhance many inflammatory processes. The up-regulated expression of astrocytic P2Y1R is crucial to participate in pain transduction under conditions of nerve injury and peripheral inflammation considering that P2Y1R is potentially involved in glutamate release and synaptic transmission. This study indicates that the expression of P2Y1R in the spinal cord was increased accompanied by the activation of A1 phenotype astrocytes in the rat model of spinal nerve ligation (SNL). Astrocyte-specific knockdown of P2Y1R alleviated SNL-induced nociceptive responses and mitigated A1 reactive astrocytes, which subsequently increased GLT-1 expression. Conversely, in naïve rats, P2Y1R over-expression induced a canonical NP-like phenotype and spontaneous hypernociceptive responses and increased the concentration of glutamate in the spinal dorsal horn. Besides, our in vitro data showed that the proinflammatory cytokine tumour necrosis factor-alpha contributes to A1/A2 astrocyte reactivity and Ca2+ -dependent release of glutamate. Conclusively, our results provide novel insights that as a significant regulator of astrocytic A1/A2 polarization and neuroinflammation, P2Y1R may represent a potential target for the treatment of SNL-induced NP.

The high burden of symptoms associated with cognitive impairment in lung cancer patients: A latent class analysis.

Objective: To explore the association between the pain-fatigue-sleep disturbance-depression symptom cluster (SC) and cancer-related cognitive impairment (CRCI) in patients having lung cancer and to identify other factors influencing CRCI. Methods: A cross-sectional study was conducted to investigate 378 patients having lung cancer in China from October 2021 to July 2022. The perceived cognitive impairment scale and the general anxiety disorder-7 were used to assess patients' cognitive impairment and anxiety, respectively. The pain-fatigue-sleep disturbance-depression SC was assessed with the brief fatigue inventory, the brief pain inventory, the Patient Health Questionnaire-9, and the Athens Insomnia Scale. Latent class analysis by Mplus.7.4 was used to identify latent classes of the SC. We adjusted for covariates in the multivariable logistic regression model to examine the relationship between the pain-fatigue-sleep disturbance-depression SC and CRCI. Results: Among patients having lung cancer, two SC classes were identified: high and low symptom burden groups. In the crude model, compared to the low symptom burden group, the high symptom group had greater odds of developing CRCI (odds ratio: 10.065, 95% confidence interval: 4.138-24.478). After adjusting for covariates, in model 1, the high symptom group still had greater odds of developing CRCI (odds ratio: 5.531, 95% confidence interval: 2.133-14.336). Additionally, a diagnosis of over 6 months, anxiety, leisure activity, and a high platelet-to-lymphocyte ratio were found to be influencing factors of CRCI (all P â€‹< â€‹0.05). Conclusions: Our study revealed that a high symptom burden is a significant risk factor for CRCI, which may provide a new perspective for managing CRCI in lung patients having cancer.

Preoperative Biologics Exposure Predisposes Ulcerative Colitis Patients to a Distinct Delayed Postoperative Ileus Syndrome After Colectomy.

BACKGROUND Postoperative ileus (POI) remains the most common complication after colectomy for inflammatory bowel disease (IBD). Delayed POI (DPOI) can develop late (>14 days) after colectomy in clinical settings, with unknown etiology. The aim of this study was to address a novel entity of POI after colectomy for ulcerative colitis (UC). MATERIAL AND METHODS The data of 263 UC patients who underwent colectomy from Jan 1, 2013 to May 31, 2021 were collected. DPOI was defined as POI occurring on or after postoperative day (POD) 14 with apparent resolution from obligatory POI. Univariate and multivariate analysis were conducted to identify the risk factors for DPOI. RESULTS The rate of canonical prolonged POI and DPOI were 11.7% (31/263) and 9.9% (26/263), respectively. The pathophysiological process of DPOI demonstrated an ileus-dysbiosis-recovery triad. Two DPOI cases were diagnosed with UC-related severe enteritis and underwent re-laparotomy. Multivariate analysis showed preoperative biologics exposure was an independent risk factor for DPOI (OR 3.100 95% CI 1.261-7.619, P=0.018) and the number of biologics session/course moderately predicted the occurrence of DPOI (AUC=0.639, 95% CI=0.578-0.697, P=0.0129). CONCLUSIONS A distinct pattern of ileus was identified in a tertiary IBD center. Clarification of this syndrome complemented the spectrum of post-IPAA complications and offered experience to treat this condition.

Hope and depression: the mediating role of social support and spiritual coping in advanced cancer patients.

BACKGROUND: Depression is the most common mental disorder in patients with advanced cancer, which may lead to poor prognosis and low survival rate. This study aims to explore the serial multiple mediating roles of social support and spiritual coping between hope and depression among patients with advanced cancer. METHODS: A cross-sectional study was conducted in China between May and August 2020. A total of 442 advanced cancer patients were investigated by the following self-reported questionnaires: Herth Hope Index (HHI), Spiritual Coping Questionnaire (SCQ, Chinese version), Social Support Rating Scale (SSRS), Hospital Anxiety and Depression Scale (HADS). RESULTS: Depression was negatively correlated with hope, social support, and positive spiritual coping (P < 0.01), and positively correlated with negative spiritual coping (P < 0.01). Hope explained 16.0% of the variance in depression. Bootstrap analyses of the hope--social support--positive spiritual coping--depression showed that there were direct [B = -0.220, 95%CI(- 0.354, - 0.072)] and indirect effects of hope on depression mediated solely by social support [B = -0.122, 95%CI(- 0.200, - 0.066)] and positive spiritual coping [B = -0.112, 95%CI(- 0.217,-0.025)], or by both together [B = -0.014, 95%CI(- 0.038,-0.003)]. Similarly, the hope--social support--negative spiritual coping--depression showed that there were direct [B = -0.302, 95%CI(- 0.404, - 0.190)] and indirect effects of hope on depression mediated solely by social support [B = -0.126, 95%CI(- 0.205, - 0.071)] and negative spiritual coping [B = -0.033, 95%CI(- 0.080,-0.002)], or by both together [B = -0.010, 95%CI(- 0.030,-0.001)]. CONCLUSIONS: This study proves the hypothesis that social support and spiritual coping play intermediary roles between hope and depression. Interventions established through hope, social support and spiritual coping can effectively prevent depression from occurring.

Autophagy: A New Mechanism for Esketamine as a Depression Therapeutic.

Depression is a serious physical and mental disease, with major depressive disorder (MDD) being a hard-to-treat, life-threatening form of the condition. Currently, esketamine (ESK) is used in the clinical treatment of MDD, but the drug mechanisms continue to be unclear. In this study, we explored the therapeutic efficacy of ESK against lipopolysaccharide (LPS)-induced neuroinflammatory, autophagic, and depressive symptoms and the possible mechanisms behind them. Our study demonstrated that LPS increased cytokine levels (TNF-α, IL-1ß, IL-6), induced neuroinflammation, led to increased levels of autophagy markers, and enhanced autophagy activation, which ultimately caused depressive symptoms in mouse models. ESK inhibited autophagy via the mTOR-BDNF signaling pathway and significantly alleviated the adverse effects induced by LPS, mainly in the form of reduced levels of cytokines, apoptotic factors, and autophagic markers; elevated BDNF levels; and improved depression-like behavior. Furthermore, we were interested to know if ESK in combination with other autophagy inhibitors would have a better antidepressant effect, and we chose the autophagy inhibitor 3-MA for this attempt. Interestingly, the use of 3-MA did not attenuate or even enhance the therapeutic effect of ESK. The results suggest that, in the LPS-induced depression models, ESK conveyed an antidepressant effect via the inhibition of autophagy through the mTOR-BDNF pathway.

A nomogram to predict prolonged postoperative ileus after intestinal resection for Crohn's disease.

PURPOSE: We aim to identify the risk factors of PPOI in patients with CD and create a nomogram for prediction of PPOI for CD. METHODS: Data on 462 patients who underwent partial intestinal resection for CD in Jin-ling Hospital between January 2019 and June 2021 were retrospectively collected. Univariate and multivariate analyses were performed to determine the risk factors for PPOI and we used the risk factors to create a nomogram. Then we used the Bootstrap-Concordance index and calibration diagrams to evaluate the performance of the Nomogram. Decision curve analysis was performed to evaluate clinical practicability of the model. RESULTS: The incidence of PPOI was 27.7% (n of N). Course of CD ≥ 10 years, operation time ≥ 154 min, the lowest mean arterial pressure ≤ 76.2 mmHg, in-out balance per body weight ≥ 22.90 ml/kg, post-op day 1 infusion ≥ 2847 ml, post-op lowest K+ ≤ 3.75 mmol/L, and post-op day 1 procalcitonin ≥ 2.445 ng/ml were identified as the independent risk factors of PPOI in patients with CD. The nomogram we created by these risk factors presented with good discriminative ability (concordance index 0.723) and was moderately calibrated (bootstrapped concordance index 0.704). The results of decision curve analysis showed that the nomogram was clinically effective within probability thresholds in the 8 to 66% range. CONCLUSION: The nomogram we developed is helpful to evaluate the risk of developing PPOI after partial intestinal resection for CD. Clinicians can take more necessary measures to prevent PPOI in CD's patients or at least minimize the incidence.

The effect of health literacy on patient's perceived shared decision-making among Chinese cancer patients.

OBJECTIVES: To explore the relationship between patient's health literacy and perceived shared decision-making (SDM) among Chinese cancer patients. METHODS: A cross-sectional study was conducted involving a convenience sample of 458 cancer patients from four public hospitals in Guangzhou, China. Patients' self-reported data were collected using the Health Literacy Management Scale (HeLMS) and the nine-item Shared Decision-Making Questionnaire (SDM-Q-9). Hierarchical multiple regressions, controlling for patient-doctor relationship, social support, sociodemographic and clinical variables were conducted to explore the effect of health literacy on perceived SDM. RESULTS: Health literacy itself accounted for 68.0% of the variance in perceived SDM. Higher scores in domains "information acquisition ability," and "communication interaction ability" of HeLMS were significantly associated with a higher level of perceived SDM after controlling the covariates (R2  = 75.7%). CONCLUSIONS: Health literacy, especially the information acquisition ability and communication interaction ability, played a prominent role for Chinese cancer patients to be involved in treatment decision making.

A core outcome set for clinical trials of first- and second-degree perineal tears prevention and treatment: a study protocol for a systematic review and a Delphi survey.

BACKGROUND: Perineal tear is a common consequence of vaginal births affecting females globally. Even mild perineal tears could cause short- and long-term complications for females. Though many studies of interventions to prevent or treat perineal tears to minimize the consequences have been conducted, there is a significant heterogeneity in the outcomes measured and reported in existing studies, which makes meaningful comparison difficult and makes the generalizability to clinical practice challenging. Developing a core outcome set (COS) could solve these methodological concerns. In this paper, we report a protocol to develop a COS for clinical trials of mild perineal tears, which shall assist in establishing the evidence base and implementation of effective measures to reduce the incidence and minimize the consequences of mild perineal tears. METHODS/DESIGN: The development of this COS will be guided by a study advisory group composed of obstetricians, midwives, nursing managers, service users, and methodologists. This study will include four stages: (1) a systematic research of the literature to identify outcomes reported in prior studies, (2) a semi-structured interview with key stakeholders to collect their opinions on important outcomes, (3) a panel of experts will be invited to conduct a three-round Delphi survey to prioritize these outcomes, and (4) a consensus meeting with key stakeholders to determine the list of outcomes included in the final COS. DISCUSSION: The development of this COS will provide international standards for the outcomes to be collected and reported in all clinical trials and audits of practice, which involve prevention and treatment of first- and second-degree perineal tears for women with vaginal delivery. This will facilitate comparing and contrasting of studies and allow for combining of appropriate studies with the ultimate goal of improved perineal care for women choosing vaginal delivery. TRIAL REGISTRATION: This study was registered in the database of Core Outcome Measures in Effectiveness Trials (COMET) on June11th, 2021 ( https://comet-initiative.org/Studies/Details/1884 ).

Three-dimensional silk fibroin scaffolds incorporated with graphene for bone regeneration.

Porous three-dimensional (3D) silk fibroin (SF) scaffolds were widely applied for bone regeneration and showed excellent biocompatibility and biodegradability. Recently graphene was developed for bone scaffolds due to its osteogenic properties. Thus, we combine the SF and graphene to improve the osteogenic properties of SF scaffolds. In our study, we explored the incorporation of SF scaffolds with graphene to develop osteogenic scaffolds capable of accelerating bone formation. The 3D SF scaffolds were fabricated with different contents of graphene (0, 0.5, and 2%). Fluorescence images showed that the graphene nanosheets were homogeneously dispersed in the SF scaffolds. The addition of graphene affected the microarchitecture of the scaffolds. The G/SF scaffolds were cocultured with rat bone marrow-derived mesenchymal stem cells (rBMSCs) for 21 days. The cell morphology and cell proliferation study suggested that 0 and 0.5% G/SF scaffolds displayed good cell proliferation. In addition, immunofluorescent staining (e.g., osteonectin, osteopontin, and osteocalcin) and ALP activities indicated that the osteogenic properties was more actively exhibited on 0.5% G/SF scaffolds compared with the other groups. Our results indicated that SF scaffolds incorporated with graphene could be an appropriate scaffold for bone tissue engineering.

Astrocytic NDRG2 is critical in the maintenance of neuropathic pain.

Activation of astrocytes and abnormal synaptic glutamate metabolism are closely associated with the induction and maintenance of neuropathic pain (NP), but the exact mechanism underlying this association remains unclear. N-myc downstream-regulated gene 2 (NDRG2), a novel tumor-suppressor protein and stress-response gene, is involved in the pathogenesis of several neurodegenerative diseases. However, its role in nociceptive transduction has rarely been investigated. Here, we found that NDRG2, which was mainly expressed in the astrocytes in the central nervous system (CNS), was increased in the spinal cord of a spinal nerve ligation (SNL) rat model for NP. Suppression of NDRG2 by intrathecal injection of an NDRG2-RNAi-adenovirus significantly alleviated SNL-induced mechanical and thermal hypersensitivity, as well as elevated astrocytic glutamate transporter 1 (GLT-1) expression and downregulated pro-inflammatory cytokine levels, in the spinal dorsal horn of rats on Day 10 after SNL. Furthermore, in lipopolysaccharide (LPS)-stimulated primary astrocytic cultures derived from neonatal rats, inhibition of NDRG2 significantly reversed both the LPS-induced activation of astrocytes and decreased expression of GLT-1. By contrast, overexpression of NDRG2 by an adenoviral vector carrying NDRG2 resulted in astrocytic activation, aberrant glutamatergic neurotransmission, and spontaneous nociceptive responses in rats. Intrathecal injection of AG490, which is an inhibitor of the Janus tyrosine kinase and signal transducer and activator of the transcription 3 (JAK/STAT3) signaling pathway, significantly attenuated both mechanical and thermal hyperalgesia, as well as inhibited reactive astrocytes and restored normal expression levels of astrocytic GLT-1, in the spinal dorsal horn of NDRG2-overexpression rats. In conclusion, spinal astrocytic NDRG2 is critical in the maintenance of NP. Moreover, NDRG2 modulates astrocytic activation and inflammatory responses via regulating GLT-1 expression through the JAK/STAT3 signaling pathway. Our findings suggested that NDRG2 could be a novel therapeutic target for the treatment of NP.

Analysis of phthalate plasticizer migration from PVDC packaging materials to food simulants using molecular dynamics simulations and artificial neural network.

Based on the experimental data of gas chromatography-mass spectrometry, an improved artificial neural network was first established to predict the migration of 2-ethylhexyl phthalate (DEHP) plasticizer from poly(vinylidene chloride) (PVDC) into food simulants (ie., heptane, ethanol and water). The sensitivity analysis indicated that temperature acted as a crucial factor influencing the migration values of DEHP. Then, a combined experimental and molecular dynamic (MD) simulation was performed to understand the migration kinetics and the mechanism of DEHP. Hansen solubility parameters of three component (δd, δp, δh) were simplified into two-component solubility parameters (δvdW, δe), and the tuple was successfully applied to describe the interactions between PVDC and food simulants. The MD results showed that high interaction energy and fractional free volume in PVDC/DEHP/food simulant systems accelerated the migration of DEHP. These fundamental studies would provide significant insights into the migration of environmental contaminants.

Clinical management of cancer-related fatigue in hospitalized adult patients: a best practice implementation project.

OBJECTIVES: This project aimed to identify and promote evidence-based practice in the management of cancer related fatigue (CRF) in the oncology unit of Nanfang Hospital, affiliated with the Southern Medical University in People's Republic of China. INTRODUCTION: Cancer-related fatigue is one of the most common symptoms in patients with cancer and significantly affects their functioning and quality of life. However, it is often inadequately addressed and evidence-based practices are not always followed. METHODS: The Joanna Briggs Institute (JBI) has a validated audit and feedback tool to assist with best practice implementation audits. The JBI Practical Application of Clinical Evidence System (PACES) was used in this project. A three-phase project was undertaken: i) a pre-implementation audit of current practice against evidence-based audit criteria, ii) identification of barriers and implementation of strategies to improve practice using the JBI Getting Research into Practice (GRiP) tool and iii) a post-implementation audit. RESULTS: The baseline audit results identified non-compliance to best practice in all areas of CRF. Strategies to improve practice involved relevant education for nurses, establishment of a CRF management routine and related documentation systems and displaying and distributing educational materials for the patients. Improved compliance was shown across all audit criteria in post-evaluation. CONCLUSIONS: The implementation of institution specific evidence-based resources demonstrated immediate improvement in CRF management and practice. Continuous effort is required to maintain changes and further improve practice. Future projects should focus on measuring the impact of changed practice on patient outcomes.

Tailoring Dielectric and Actuated Properties of Elastomer Composites by Bioinspired Poly(dopamine) Encapsulated Graphene Oxide.

In this study, we obtained dielectric elastomer composites with controllable dielectric and actuated properties by using a biomimetic method. We used dopamine (DA) to simultaneously coat the graphene oxide (GO) and partially reduce GO by self-polymerization of DA on GO. The poly(dopamine) (PDA) coated GO (GO-PDA) was assembled around rubber latex particles by hydrogen bonding interaction between carboxyl groups of carboxylated nitrile rubber (XNBR) and imino groups or phenolic hydroxyl groups of GO-PDA during latex compounding, forming a segregated GO-PDA network at a low percolation threshold. The results showed that the introduction of PDA on GO prevented the restack of GO in the matrix. The dielectric and actuated properties of the composites depend on the thickness of PDA shell. The dielectric loss and the elastic modulus decrease, and the breakdown strength increases with increasing the thickness of PDA shell. The maximum actuated strain increases from 1.7% for GO/XNBR composite to 4.4% for GO-PDA/XNBR composites with the PDA thickness of about 5.4 nm. The actuated strain at a low electric field (2 kV/mm) obviously increases from 0.2% for pure XNBR to 2.3% for GO-PDA/XNBR composite with the PDA thickness of 1.1 nm, much higher than that of other DEs reported in previous studies. Thus, we successfully obtained dielectric composites with low dielectric loss and improved breakdown strength and actuated strain at a low electric field, facilitating the wide application of dielectric elastomers.

Graphene encapsulated rubber latex composites with high dielectric constant, low dielectric loss and low percolation threshold.

A dielectric composite with high dielectric constant, low dielectric loss and low percolation threshold was prepared by using the combined strategy of encapsulating of graphene oxide nanosheets (GONS) on carboxylated nitrile rubber (XNBR) latex particles and the in situ thermal reduction in GONS at a moderate temperature. The encapsulation of GONS on XNBR latex particles was mainly realized via the hydrogen bonding interactions between GONS and XNBR during latex mixing. A segregated graphene network was obtained at a low content of thermally reduced graphene (TRG), resulting in a low percolation threshold (0.25 vol.%). The dielectric constant at 100 Hz obviously increased from 23 for pure XNBR to 2211 and 5542 for the composite with 0.5 vol.% and 0.75 vol.% of TRG, respectively. The dielectric loss of the composites retained at a low value (less than 1.5). Meanwhile, the elastic modulus only slightly increased with the presence of 0.1-0.5 vol.% of TRG, keeping the good flexibility of the dielectric composites. This study provides a simple, low-cost and effective method to prepare high performance dielectric composites, facilitating the wide application of dielectric materials.

Water-compatible molecularly imprinted microspheres in pipette tip solid-phase extraction for simultaneous determination of five fluoroquinolones in eggs.

New water-compatible molecularly imprinted microspheres were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using 3-(2-carboxyethylsulfanylthiocarbonyl-sulfanyl) propionic acid as a hydrophilic chain-transfer agent, and employed as the sorbent of pipet tip molecularly imprinted solid-phase extraction (PT-MISPE) for rapid extraction and screening of ofloxacin, pefloxacin, norfloxacin, ciprofloxacin, and enrofloxacin in eggs. In comparison to conventional SPE methods, the presented PT-MISPE showed special selectivity, easy operation, and accessible device without expensive SPE apparatus. The presented PT-MISPE method combined advantages of dummy molecularly imprinted polymers and pipet tip solid-phase extraction. The presented method was linear over a calibration range of 25-2500 µg/kg with the limits of detections of 0.53-1.07 µg/kg. Good recoveries (89.1-102.5%) were achieved with relative standard deviations of 2.6-4.8%.

Ionic liquids modified dummy molecularly imprinted microspheres as solid phase extraction materials for the determination of clenbuterol and clorprenaline in urine.

New ionic liquid modified dummy molecularly imprinted microspheres (DMIMs) were synthesized by aqueous suspension polymerization using phenylephrine as dummy template and 1-allyl-3-ethylimidazolium bromide as co-functional monomer. The obtained DMIMs were characterized by Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM), and empolyed as the special sorbent of solid-phase extraction for isolation of clenbuterol (CLB) and clorprenaline (CLP) from urine sample. The results indicated that the ionic liquid modified polymers were monodispersed microspheres and had high selectivity and adsorbability to CLB and CLP, and the matrix interferences could be efficiently eliminated from the samples. Meanwhile, the effect of template leakage of DMIMs on quantitative analysis was avoided. Compared with other commercial sorbents (HLB, PCX, C18 and SCX), the DMIMs exhibited higher affinity and purification ability to CLP and CLB. Under the optimized conditions, good linearity was observed in a range of 0.90-400µgL(-1) (r(2)=0.9999) with LOD of 0.19 and 0.070µgL(-1) for CLP and CLB, respectively. The recoveries at three spiked levels were ranged from 93.3% to 106% with RSD≤5.6% (n=3).