Hybrid plasmonic aerogel with tunable hierarchical pores for size-selective multiplexed detection of VOCs with ultrahigh sensitivity

Sensitive and rapid identification of volatile organic compounds (VOCs) at ppm level with complex composition is vital in various fields ranging from respiratory diagnosis to environmental safety. Herein, we demonstrate a SERS gas sensor with size-selective and multiplexed identification capabilities for VOCs by executing the pre-enrichment strategy. In particular, the macro-mesoporous structure of graphene aerogel and micropores of metal-organic frameworks (MOFs) significantly improved the enrichment capacity (1.68 mmol/g for toluene) of various VOCs near the plasmonic hotspots. On the other hand, molecular MOFs-based filters with different pore sizes could be realized by adjusting the ligands to exclude undesired interfering molecules in various detection environments. Combining these merits, graphene/AuNPs@ZIF-8 aerogel gas sensor exhibited outstanding label-free sensitivity (up to 0.1 ppm toluene) and high stability (RSD=14.8%, after 45 days storage at room temperature for 10 cycles) and allowed simultaneous identification of multiple VOCs in a single SERS measurement with high accuracy (error < 7.2%). We visualize that this work will tackle the dilemma between sensitivity and detection efficiency of gas sensors and will inspire the design of next-generation SERS technology for selective and multiplexed detection of VOCs.

Charge transfer in TiO2-based photocatalysis: fundamental mechanisms to material strategies

Semiconductor-based photocatalysis has attracted significant interest due to its capacity to directly exploit solar energy and generate solar fuels, including water splitting, CO2 reduction, pollutant degradation, and bacterial inactivation. However, achieving the maximum efficiency in photocatalytic processes remains a challenge owing to the speedy recombination of electron-hole pairs and the limited use of light. Therefore, significant endeavours have been devoted to addressing these issues. Specifically, well-designed heterojunction photocatalysts have been demonstrated to exhibit enhanced photocatalytic activity through the physical distancing of electron-hole pairs generated during the photocatalytic process. In this review, we provide a systematic discussion ranging from fundamental mechanisms to material strategies, focusing on TiO2-based heterojunction photocatalysts. Current efforts are focused on developing heterojunction photocatalysts based on TiO2 for a variety of photocatalytic applications, and these projects are explained and assessed. Finally, we offer a concise summary of the main insights and challenges in the utilization of TiO2-based heterojunction photocatalysts for photocatalysis. We expect that this review will serve as a valuable resource to improve the efficiency of TiO2-based heterojunctions for energy generation and environmental remediation.

Wearable Plasmonic Sensors Engineered via Active-Site Maximization of TiVC MXene for Universal Physiological Monitoring at the Molecular Level

Two-dimensional transition metal carbon/nitrides (MXenes) are promising candidates to revolutionize next-generation wearable sensors as high-performance surface-enhanced Raman scattering (SERS) substrates. However, low sensitivity of pure MXene nanosheets and weak binding force or uncontrolled in situ growth of plasmonic nanoparticles on hybrid MXene composites limit their progress toward universal and reliable sensors. Herein, we designed and manufactured a highly sensitive, structurally stable wearable SERS sensor by in situ fabrication of plasmonic nanostructures on the flexible TiVC membranes via the maximization of chemically reducing sites using alkaline treatment. DFT calculations and experimental characterization demonstrated that the hydroxyl functional groups on the surface of MXenes can facilitate the reduction of metal precursors and the nucleation of gold nanoparticles (AuNPs) and can be covalently attached to AuNPs. Thus, the fabricated flexible TiVC-OH-Au sensor satisfied the rigorous mechanical requirements for wearable sensors. In addition, combining the electromagnetic (EM) enhancement from dense AuNPs formed by the activation of nucleation sites and charge transfer (CT) between target molecule and substrate induced by the abundant DOS near the Fermi level of TiVC, the fabricated sensor exhibits ultrasensitivity, long-term stability, good signal repeatability, and excellent mechanical durability. Moreover, the proof-of-concept application of the wearable SERS sensor in sweat sensing was demonstrated to monitor the content of nicotine, methotrexate, nikethamide, and 6-acetylmorphine in sweat at the molecular level, which was an important step toward the universality and practicality of the wearable sensing technology.

MOF Derivatives with Gradient Structure Anchored on Carbon Foam for High-Performance Electromagnetic Wave Absorption

The impedance matching and high loss capabilities of composites with homogeneous distribution are limited owing to high addition and lack of structural design. Developing composites with heterogeneous distribution can achieve strong and wide electromagnetic (EM) wave absorption. However, challenges such as complex design and unclear absorption mechanisms still exist. Herein, a novel composite with a heterogeneous distribution gradient is successfully constructed via MOF derivatives Co@ nitrogen-doped carbon (Co@NC) anchored on carbon foam (CF) matrix (MDCF). Notably, the concentration of MOF can easily control the gradient structure. In particular, the morphologies of MOF derivatives on the surface of CF undergo a transition from the collapse of the inner layer to the integrity of the outer layer, accompanied by a continuous reduction in the size of Co nanoparticles. Correspondingly, enhanced interface polarization from the core-shell of Co@NC and good impedance matching of MDCF can be obtained. The optimized MDCF exhibits the minimum reflection loss of -68.18 dB at 2.01 mm and effective absorption bandwidth covering the entire X-band. Moreover, MDCF exhibits lightweight characteristics, excellent compressive strength, and low radar cross-section reduction. This work highlights the immense potential of composites with heterogeneous distribution for achieving high-performance EM wave absorption.

Triple-enhanced Raman scattering sensors from flexible MXene/Au nanocubes platform via attenuating the coffee ring effect

Developing substrates that combine sensitivity and signal stability is a major challenge in surface enhanced Raman scattering (SERS) research. Herein, we present a flexible triple-enhanced Raman Scattering MXene/Au nanocubes (AuNCs) sensor fabricated by selective filtration of Ti3C2Tx MXene/AuNCs hybrid on the Ti3C2Tx MXene membrane and subsequent treatment with 1H,1H,2H,2H-perfluoro-octyltriethoxysilane (FOTS). The resultant superhydrophobic MXene/AuNCs-FOTS membrane not only provides the SERS substrate with environmental stability, but also imparts analyte enrichment to enhance the sensitivity (LOD = 1 × 10-14 M) and reliability (RSD = 6.41%) for Rhodamine 6G (R6G) molecules owing to the attenuation of the coffee ring effect. Moreover, the triple enhancement mechanism of combining plasmonic coupling enhancement from plasmonic coupling (EM) of nearby AuNCs at lateral and longitudinal direction of MXene/AuNCs-FOTS membrane, charge transfer (CT) from Ti3C2Tx MXene and target molecules and analyte enrichment function provides the substrate with excellent SERS performance (EF = 3.19 × 109), and allows efficient quantification of biomarkers in urine. This work could provide new insights into MXenes as building blocks for high-performance substrates and fill existing gaps in SERS techniques.

High-efficient adsorption for versatile adsorbates by elastic reduced graphene oxide/Fe3O4 magnetic aerogels mediated by carbon nanotubes

Fabrication of highly elastic three-dimensional aerogel adsorbents with outstanding adsorption capacities is a long pursuit for the treatment of industrial contaminated water. In this work, a magnetic reduced graphene oxide (rGO)/Fe₃O₄/carbon nanotubes (CNTs) aerogel material was constructed by the electrostatic attraction between the negatively charged GO and positively charged CNTs following a one-pot water bath treatment. The as-synthesized aerogel demonstrated high compressive stress (28.4 kPa) and lower density (24.11 mg/cm³) with exceptional adsorption capacities for versatile adsorbates which are attributed to CNTs and magnetic Fe₃O₄ nanoparticles. The effect of pH, initial concentration of adsorbates (dyes, Cd (ІІ) ions, organic solvents, and pump oil), content of CNTs and cyclic times on the adsorption capacities of the aerogel were investigated in detail. Furthermore, from simulation, the adsorption kinetics, and thermodynamics of the aerogel for adsorbates were more satisfied by endothermic quasi-second-order kinetic model with characteristic physical adsorption. Thus, the optimized rGO/Fe₃O₄/CNTs-10 aerogel adsorbent can be used as a powerful and versatile tool to deal with contaminated industrial or domestic wastewater.

Plasmonic Coupling of Au Nanoclusters on a Flexible MXene/Graphene Oxide Fiber for Ultrasensitive SERS Sensing

High sensitivity, good signal repeatability, and facile fabrication of flexible surface enhanced Raman scattering (SERS) substrates are common pursuits of researchers for the detection of probe molecules in a complex environment. However, fragile adhesion between the noble-metal nanoparticles and substrate material, low selectivity, and complex fabrication process on a large scale limit SERS technology for wide-ranging applications. Herein, we propose a scalable and cost-effective strategy to a fabricate sensitive and mechanically stable flexible Ti₃C₂T_x MXene@graphene oxide/Au nanoclusters (MG/AuNCs) fiber SERS substrate from wet spinning and subsequent in situ reduction processes. The use of MG fiber provides good flexibility (114 MPa) and charge transfer enhancement (chemical mechanism, CM) for a SERS sensor and allows further in situ growth of AuNCs on its surface to build highly sensitive hot spots (electromagnetic mechanism, EM), promoting the durability and SERS performance of the substrate in complex environments. Therefore, the formed flexible MG/AuNCs-1 fiber exhibits a low detection limit of 1 × 10^-11 M with a 2.01 × 10⁹ enhancement factor (EF_exp), signal repeatability (RSD = 9.80%), and time retention (remains 75% after 90 days of storage) for R6G molecules. Furthermore, the l-cysteine-modified MG/AuNCs-1 fiber realized the trace and selective detection of trinitrotoluene (TNT) molecules (0.1 μM) via Meisenheimer complex formation, even by sampling the TNT molecules at a fingerprint or sample bag. These findings fill the gap in the large-scale fabrication of high-performance 2D materials/precious-metal particle composite SERS substrates, with the expectation of pushing flexible SERS sensors toward wider applications.

Controllable graphitization degree of carbon foam bulk toward electromagnetic wave attenuation loss behavior

The graphitization degree is of great importance for determining the electromagnetic (EM) wave attenuation loss behavior. The conductive loss is considered to be the mechanism resulting from tailoring the graphitization degree. There is a lack of in-depth research on the dipole polarization caused by defects and functional groups and the interface polarization caused by graphite/amorphous carbon. Herein, lightweight carbon foam (CF) bulk derived from mesophase pitch was prepared to clarify the effect of the graphitization degree systematically. The results demonstrate that with an increase graphitization degree, the interfacial polarization improves and dipole polarization decreases. The synergistic effect of conduction loss and dipole and interfacial polarization dominates the impedance matching and further changes the EM loss behavior of CFs. Particularly, the minimum reflection loss is - 16.69 dB and effective absorption bandwidth is 3.63 GHz, the EM interference shielding effectiveness attains 35.13 dB and the compressive strength is up to 11.73 MPa when the optimal graphitization degree is achieved. Therefore, this work elucidates the effect of the interface polarization of graphite/amorphous carbon, thus providing a valuable insight into the design of advanced carbon-based materials for EM wave absorption and shielding.

Extended visible light driven photocatalytic hydrogen generation by electron induction from g-C3N4 nanosheets to ZnO through the proper heterojunction

The alarming energy crises has forced the scientific community to work for sustainable energy modules to meet energy requirements. As for this, ZnO/g-C3N4 nanocomposites with proper heterojunction were fabricated by coupling a proper amount of ZnO with 2D graphitic carbon nitride (g-C3N4) nanosheets and the obtained nanocomposites were applied for photocatalytic hydrogen generation from water under visible light illumination (λ > 420 nm). The morphologies and the hydrogen generation performance of fabricated photocatalysts were characterized in detail. Results showed that the optimized 5ZnO/g-C3N4 nanocomposite produced 70 µmol hydrogen gas in 1 h compare to 8 µmol by pure g-C3N4 under identical illumination conditions in the presence of methanol without the addition of cocatalyst. The much improved photoactivities of the nanocomposites were attributed to the enhanced charge separation through the heterojunction as confirmed from photoluminescence study, capacity of the fabricated samples for •OH radical generation and steady state surface photovoltage spectroscopic (SS-SPS) measurements. We believe that this work would help to fabricate low cost and effective visible light driven photocatalyst for energy production.

How to assess severity in males with eating disorders? The DSM-5 severity index versus severity based on drive for thinness

Introduction

The Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) introduced severity indices for Eating Disorders (ED).

Objectives

This study assessed in a male ED sample the DSM-5 severity indices for Anorexia Nervosa (AN), Bulimia Nervosa (BN) and Binge Eating Disorder (BED) and compared them to an alternative transdiagnostic drive for thinness (DT) severity category and a combined DSM-5/DT severity categorization

Methods

178 males with EDs were classified using: a.) a DT categorisation based on the EDI-2 DT subscale; b.) the DSM-5 severity categories for AN, BN and BED and c.) a combination of the DT and the DSM-5 severity categorisation. These severity classifications were then compared based on psychopathology and personality.

Results

For the DSM-5 severity indices, the “mild” category was most prevalent for AN and BN, and the “moderate to extreme” group for BED. For the EDI-2 DT severity classification, the “mild” category was overrepresented in all subtypes. For the combined DSM-5/DT categorization, the “mild combined” severity group was the most prevalent for AN, while for BN and BED the “severe/extreme” combined group was most prevalent. Clinically significant findings were strongest for the DT categorization followed by the combined DSM-5/DT approach. Almost non-significant findings were revealed for the DSM-5 severity categories for all ED subtypes. These findings were most pronounced for AN and BN and almost non-existent for BED.

Conclusions

Our findings provide support for DT as an alternative transdiagnostic severity category for EDs in males that may be more meaningful than the DSM-5 severity indices for AN and BN, but not BED.

Disclosure

No significant relationships.

Review on the hazardous applications and photodegradation mechanisms of chlorophenols over different photocatalysts

Chlorophenols are very important environmental pollutants, which have created huge problems for both aquatic and terrestrial lives. Therefore, their removal needs urgent, effective, and advanced technologies to safeguard our environment for future generation. This review encompasses a comprehensive study of the applications of chlorophenols, their hazardous effects and photocatalytic degradation under light illumination. The effect of various factors such as pH and presence of different anions on the photocatalytic oxidation of chlorophenols have been elaborated comprehensively. The production of different oxidizing agents taking part in the photodegradation of chlorophenols are given a bird eye view. The photocatalytic degradation mechanism of different chlorophenols over various photocatalyts has been discussed in more detail and elaborated that how different photocatalysts degrade the same chlorophenols with the aid of different oxidizing agents produced during photocatalysis. Finally, a future perspective has been given to deal with the effective removal of these hazardous pollutants from the environment.

A systematic review and meta-analysis on the DSM-5 severity specifiers for eating disorders

Introduction

The DSM-5 introduced severity indicies for the first time.

Objectives

We conducted a systematic review and synthesis the frequency of each DSM-5 severity categories (i.e., mild, moderate, severe and extreme severe) for Anorexia Nervosa (AN), Bulimia Nervosa (BN) and Binge Eating Disorders (BED), and to evaluate studies that assess the clinical utility of these severity specifiers for all eating disorders (ED) subtypes.

Methods

Five databases (EMBASE, MEDLINE, PsycARTICLES, PsycINFO, and ProQuest) were used to identify for both academic and grey literature published from 2013 until July 8, 2020. Twenty-five studies were retrieved for the systematic review based on the inclusion and exclusion criteria, and up to six studies were qualified for meta-analysis

Results

We found limited support for the current DSM-5 severity ratings for all ED indices, as the majority of ED severity groups were not significantly distinguishable in overall ED psychopathology (mean effect size ranged from .02 to .5). The value of the DSM-5 severity ratings was further devalued as 56.91% to 80.52% of individuals with AN, BN, and BED were categorized into mild and moderate groups. However, there was significant heterogeneity between the studies (p< .001), and some of these heterogeneities were explained by differences in study settings and measurement of eating disorder psychopathology.

Conclusions

Overall, the current study provided little support for the DSM-5 severity ratings for EDs, thus it is suggested that further exploration in alternative severity classification approach is needed.

Disclosure

No significant relationships.

Do women with differing levels of trait eating pathology experience daily stress and body dissatisfaction differently?

Introduction

Studies have suggested that stress predicts both body dissatisfaction (BD) and disordered eating (DE) patterns. However, the mechanisms of this process are not entirely clear and could be elucidated through further exploration in daily life.

Objectives

The purpose of this study was to 1) explore the concurrent and lagged relationship between stress and BD in the daily life of individuals with differing levels of trait eating pathology (EP) and 2) to investigate whether maladaptive coping moderated these relationships.

Methods

107 female participants (mean age = 26.92) completed an online survey about stress, coping strategies and trait EP. Participants used a smartphone app to report on state stress, BD and DE six times a day for seven days

Results

Individuals with elevated trait EP experienced a significantly higher frequency of stress events (b = 0.04). Participants’ use of maladaptive coping significantly increased state stress (b = 0.41), but was not moderated by EP. Participants’ state stress and BD measured at the same time point (concurrent assessment) were significantly related (b = 0.13). Either stress or BD at the previous time point did not significantly predict changes in the other (lagged assessment, b = 0.02, b = -0.09, respectively). The aforementioned state-based associations were not moderated by trait EP

Conclusions

Women with more severe EP were found to experience stress more frequently. Maladaptive coping strategies were related to stress, but not moderated by EP. The association between stress and BD from concurrent but not lagged assessment highlights the importance of assessing and targeting momentary stress levels.

Disclosure

No significant relationships.

Repeatable and Reprogrammable Shape Morphing from Photoresponsive Gold Nanorod/Liquid Crystal Elastomers

Liquid crystal elastomers (LCEs) are of interest for applications such as soft robotics and shape-morphing devices. Among the different actuation mechanisms, light offers advantages such as spatial and local control of actuation via the photothermal effect. However, the unwanted aggregation of the light-absorbing nanoparticles in the LCE matrix will limit the photothermal response speed, actuation performance, and repeatability. Herein, a near-infrared-responsive LCE composite consisting of up to 0.20 wt% poly(ethylene glycol)-modified gold nanorods (AuNRs) without apparent aggregation is demonstrated. The high Young's modulus, 20.3 MPa, and excellent photothermal performance render repeated and fast actuation of the films (actuation within 5 s and recovery in 2 s) when exposed to 800 nm light at an average output power of ≈1.0 W cm^-2 , while maintaining a large actuation strain (56%). Further, it is shown that the same sheet of AuNR/LCE film (100 µm thick) can be morphed into different shapes simply by varying the motifs of the photomasks.

A Facile Method to Prepare Silver Doped Graphene Combined with Polyaniline for High Performances of Filter Paper Based Flexible Electrode

A flexible filter paper based composite electrode was prepared via the convenient one-step synthesis of silver doped graphene for the first time, followed by in-situ polymerization of aniline monomers. Using L-ascorbic acid for simultaneous reduction of grapheme oxide and silver nitrate, we provided a new and green method to prepare graphene hybrid sheets without toxicity. It was found that the as-fabricated hybrid electrode formed a three-dimensional porous architecture, which not only increased the specific surface area of composite, but also facilitated the ion diffusion of the electrolyte. In addition, according to the tests of electrochemical performances, the flexible hybrid electrode subsequently exhibited exceptional specific capacitance of 437.3 F/g, energy density of 1133.5 W·h/kg and power density of 88.8 kW/kg, respectively. Meanwhile, the as-prepared hybrid demonstrated a good cycling stability with only 10.99% specific capacitance deterioration after 5000 times of cycling. This preparation technology presented here shows great potential for the development and application of wearable and portable energy storage devices, particularly for flexible supercapacitors. Moreover, this study puts forward a general, simple and low-cost route of fabricating a novel flexible electrode on a large scale, eventually for environmental protection.

Factors affecting radiotherapy prescribing patterns in the post-mastectomy setting

Background

Radiation therapy (rt) after mastectomy for breast cancer can improve survival outcomes, but has been associated with inferior cosmesis after breast reconstruction. In the literature, rt dose and fractionation schedules are inconsistently reported. We sought to determine the pattern of rt prescribing practices in a provincial rt program for patients treated with mastectomy and reconstruction.

Methods

Women diagnosed with stages 0-iii breast cancer between January 2012 and December 2013 and treated with curative-intent rt were identified from a clinicopathology database. Patient demographic, tumour, and treatment information were extracted. Of the identified patients, those undergoing mastectomy were the focus of the present analysis.

Results

Of 4016 patients identified, 1143 (28%) underwent mastectomy. The patients treated with mastectomy had a median age of 57 years, and 37% of them underwent reconstruction. Treatment with more than 16 fractions of rt was associated with autologous reconstruction [odds ratio (or): 37.2; 95% confidence interval (ci): 11.2 to 123.7; p < 0.001], implant reconstruction (or: 93.3; 95% ci: 45.3 to 192.2; p < 0.001), and treating centre. Hypofractionated treatment was associated with older age (or: 0.94; 95% ci: 0.92 to 0.96; p < 0.001), and living more than 400 km from a treatment centre (or: 0.37; 95% ci: 0.16 to 0.86; p = 0.02).

Conclusions

Prescribing practices in breast cancer patients undergoing mastectomy are influenced by reconstruction intent, age, nodal status, and distance from the treatment centre. Those factors should be considered when making treatment decisions.

Assessing post-radiotherapy handover notes from a family physician perspective

Background

Across our province, post-radiotherapy (rt) handover notes are sent to family physicians (fps) after rt. Based on previous fp feedback, we created a revised post-radiotherapy handover note with more information requested by fps. The purpose of this study was to determine whether the revised handover note improved the note as a communication aid.

Methods

Potential common and rare treatment side effects, oncologist contact information, and treatment intent were added to the revised handover note. Both versions were sent alongside a questionnaire to fps. Paired t-tests were carried out to compare satisfaction differences.

Results

There was a response rate of 37% for the questionnaires. Significantly greater clarity in the following categories was observed: responsibility for patient follow-up (mean score improvement of 1.2 on a 7-point Likert scale, p < 0.001), follow-up schedule (1.1, p < 0.001) as well as how and when to contact the oncologist (1.4, p = 0.001). Family physicians were also more content with how the institute transitioned care back to them (1.5, p = 0.012). Overall, fps were generally satisfied with the content of the revised post-rt handover note and noted improvement over the previous version. The frequency of investigations and institute supports initiated such as counselling services were suggested further additions.

Conclusions

The inclusion of potential treatment side effects, oncologist contact information, treatment intent and a well-laid out follow-up schedule were essential information needed by fps for an effective post-rt completion note. With these additions, the revised post-rt handover note showed significant improvement.

Intraoperative serum lactate is not a predictor of survival after glioblastoma surgery

BACKGROUND

Cancer cells can produce lactate in high concentrations. Two previous studies examined the clinical relevance of serum lactate as a biomarker in patients with brain tumors. Patients with high-grade tumors have higher serum concentrations of lactate than those with low-grade tumors. We hypothesized that serum lactic could be used of biomarker to predictor of survival in patients with glioblastoma (GB).

METHODS

This was a retrospective study. Demographic, lactate concentrations and imaging data from 275 adult patients with primary GB was included in the analysis. The progression free survival (PFS) and overall survival (OS) rates were compared in patients who had above and below the median concentrations of lactate. We also investigated the correlation between lactate concentrations and tumor volume. Multivariate analyses were conducted to test the association lactate, tumor volume and demographic variables with PFS and OS.

RESULTS

The median serum concentration of lactate was 2.3mmol/L. A weak correlation was found between lactate concentrations and tumor volume. Kaplan-Meier curves demonstrated similar survival in patients with higher or lower than 2.3mmol/L of lactate. The multivariate analysis indicated that the intraoperative levels of lactate were not independently associated with changes in survival. On another hand, a preoperative T1 volume was an independent predictor PFS (HR 95%CI: 1.41, 1.02-1.82, p=0.006) and OS (HR 95%CI: 1.47, 1.11-1.96, p=0.006).

CONCLUSION

This retrospective study suggests that the serum concentrations of lactate cannot be used as a biomarker to predict survival after GB surgery. To date, there are no clinically available serum biomarkers to determine prognosis in patients with high-grade gliomas. These tumors may produce high levels of lactic acid. We hypothesized that serum lactic could be used of biomarker to predictor of survival in patients with glioblastoma (GB). In this study, we collected perioperative and survival data from 275 adult patients with primary high-grade gliomas to determine whether intraoperative serum acid lactic concentrations can serve as a marker of prognosis. The median serum concentration of lactate was 2.3mmol/L. Our analysis indicated the intraoperative levels of lactate were not independently associated with changes in survival. This retrospective study suggests that the serum concentrations of lactate cannot be used as a biomarker to predict survival after GB surgery.

Self-propagating Combustion Triggered Synthesis of 3D Lamellar Graphene/BaFe12O19 Composite and Its Electromagnetic Wave Absorption Properties

The synthesis of 3D lamellar graphene/BaFe₁₂O₁₉ composites was performed by oxidizing graphite and sequentially self-propagating combustion triggered process. The 3D lamellar graphene structures were formed due to the synergistic effect of the tremendous heat induced gasification as well as huge volume expansion. The 3D lamellar graphene/BaFe₁₂O₁₉ composites bearing 30 wt % graphene present the reflection loss peak at −27.23 dB as well as the frequency bandwidth at 2.28 GHz (< −10 dB). The 3D lamellar graphene structures could consume the incident waves through multiple reflection and scattering within the layered structures, prolonging the propagation path of electromagnetic waves in the absorbers.

Direct in situ synthesis of a 3D interlinked amorphous carbon nanotube/graphene/BaFe12O19 composite and its electromagnetic wave absorbing properties

The 3D interlinked amorphous carbon nanotube (ACNT)/reduced graphene oxide (RGO)/BaFe₁₂O₁₉ (BF) composite was directly prepared by a self-propagation combustion process.

Preparation and electromagnetic wave absorbing properties of 3D graphene/pine needle-like iron nano-acicular whisker composites

The improvement of high reflection loss and broad frequency bandwidth for electromagnetic wave absorption materials is a long-term effort.

In situ synthesis and electromagnetic wave absorbing properties of sandwich microstructured graphene/La-doped barium ferrite nanocomposite

The development of high reflection loss and broad frequency bandwidth for electromagnetic wave absorbing materials has been pursued for a long time.

Expanded graphite embedded with aluminum nanoparticles as superior thermal conductivity anodes for high-performance lithium-ion batteries

The development of high capacity and long-life lithium-ion batteries is a long-term pursuing and under a close scrutiny. Most of the researches have been focused on exploring electrode materials and structures with high store capability of lithium ions and at the same time with a good electrical conductivity. Thermal conductivity of an electrode material will also have significant impacts on boosting battery capacity and prolonging battery lifetime, which is, however, underestimated. Here, we present the development of an expanded graphite embedded with Al metal nanoparticles (EG-MNPs-Al) synthesized by an oxidation-expansion process. The synthesized EG-MNPs-Al material exhibited a typical hierarchical structure with embedded Al metal nanoparticles into the interspaces of expanded graphite. The parallel thermal conductivity was up to 11.6 W·m^-1·K^-1 with a bulk density of 453 kg·m^-3 at room temperature, a 150% improvement compared to expanded graphite (4.6 W·m^-1·K^-1) owing to the existence of Al metal nanoparticles. The first reversible capacity of EG-MNPs-Al as anode material for lithium ion battery was 480 mAh·g^-1 at a current density of 100 mA·g^-1, and retained 84% capacity after 300 cycles. The improved cycling stability and system security of lithium ion batteries is attributed to the excellent thermal conductivity of the EG-MNPs-Al anodes.

High-sensitivity C-reactive protein predicts adverse cardiovascular events in patients with Takayasu arteritis with coronary artery involvement

The study aimed to assess the association of high-sensitivity C-reactive protein (hsCRP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) to major adverse cardiovascular events (MACE) in Takayasu arteritis (TA) patients with coronary artery disease (CAD). Data on 60 TA patients with CAD and 60 age- and severity-matched patients with CAD hospitalized in Fuwai Hospital from 2005 to August 2014 were assessed. The clinical features, laboratory data, coronary angiographic findings, treatment, and follow-up outcomes were summarized retrospectively. MACE were defined as death from cardiac causes, myocardial infarction, nonfatal target vessel revascularization, or rehospitalization due to unstable or progressive angina. CAD patients had more atherogenic lipid and lipoprotein profiles such as lower levels of high-density lipoprotein cholesterol (HDL-C) (1.0 ± 0.2 vs. 1.3 ± 0.3 mmol/L, p = 0.01) and higher levels of low-density lipoprotein cholesterol (LDL-C) (2.5 ± 0.9 vs. 2.2 ± 1.1 mmol/L, p = 0.04) in contrast with TA-CAD patients. During a mean follow-up period of 3.2 years, 31 patients with Takayasu coronary arteritis reached the endpoint. Multivariate Cox proportional hazards model demonstrated that log(hsCRP) (HR = 5.3, 95 % CI = 1.1-27.8, p = 0.04) was a significant and independent predictor of MACE in patients with Takayasu coronary arteritis. Elevated baseline levels of hsCRP predict cardiovascular events, independent of other prognostic markers in TA-related CAD patients.

Performance of dielectric nanocomposites: matrix-free, hairy nanoparticle assemblies and amorphous polymer-nanoparticle blends

Demands to increase the stored energy density of electrostatic capacitors have spurred the development of materials with enhanced dielectric breakdown, improved permittivity, and reduced dielectric loss. Polymer nanocomposites (PNCs), consisting of a blend of amorphous polymer and dielectric nanofillers, have been studied intensely to satisfy these goals; however, nanoparticle aggregates, field localization due to dielectric mismatch between particle and matrix, and the poorly understood role of interface compatibilization have challenged progress. To expand the understanding of the inter-relation between these factors and, thus, enable rational optimization of low and high contrast PNC dielectrics, we compare the dielectric performance of matrix-free hairy nanoparticle assemblies (aHNPs) to blended PNCs in the regime of low dielectric contrast to establish how morphology and interface impact energy storage and breakdown across different polymer matrices (polystyrene, PS, and poly(methyl methacrylate), PMMA) and nanoparticle loadings (0-50% (v/v) silica). The findings indicate that the route (aHNP versus blending) to well-dispersed morphology has, at most, a minor impact on breakdown strength trends with nanoparticle volume fraction; the only exception being at intermediate loadings of silica in PMMA (15% (v/v)). Conversely, aHNPs show substantial improvements in reducing dielectric loss and maintaining charge/discharge efficiency. For example, low-frequency dielectric loss (1 Hz-1 kHz) of PS and PMMA aHNP films was essentially unchanged up to a silica content of 50% (v/v), whereas traditional blends showed a monotonically increasing loss with silica loading. Similar benefits are seen via high-field polarization loop measurements where energy storage for ∼15% (v/v) silica loaded PMMA and PS aHNPs were 50% and 200% greater than respective comparable PNC blends. Overall, these findings on low dielectric contrast PNCs clearly point to the performance benefits of functionalizing the nanoparticle surface with high-molecular-weight polymers for polymer nanostructured dielectrics.

High-transparency polymer nanocomposites enabled by polymer-graft modification of particle fillers

The role of polymeric ligands on the optical transparency of polymer-matrix composites is analyzed by evaluating the effect of surface modification on the scattering cross-section of particle fillers in uniform particle dispersions. For the particular case of poly(styrene-r-acrylonitrile)-grafted silica particles embedded in poly(methyl methacrylate), it is shown that the tethering of polymeric chains with appropriate optical properties (such as to match the effective refractive index of the brush particle to the embedding matrix) facilitates the reduction of the particle scattering cross-section by several orders of magnitude as compared to pristine particle analogues. The conditions for minimizing the scattering cross-section of particle fillers by polymer-graft modification are established on the basis of effective medium as well as core-shell Mie theory and validated against experimental data on uniform liquid and solid particle dispersions. Effective medium theory is demonstrated to provide robust estimates of the "optimum polymer-graft composition" to minimize the scattering cross-section of particle fillers even in the limit of large particle dimensions (comparable to the wavelength of light). The application of polymer-graft modification to the design of large (500 nm diameter) silica particle composites with reduced scattering cross-section is demonstrated.

Characterisation of osteoarthritis in a small animal model of type 2 diabetes mellitus

Objectives

Our objective in this article is to test the hypothesis that type 2 diabetes mellitus (T2DM) is a factor in the onset and progression of osteoarthritis, and to characterise the quality of the articular cartilage in an appropriate rat model.

Methods

T2DM rats were obtained from the UC Davis group and compared with control Lewis rats. The diabetic rats were sacrificed at ages from six to 12 months, while control rats were sacrificed at six months only. Osteoarthritis severity was determined via histology in four knee quadrants using the OARSI scoring guide. Immunohistochemical staining was also performed as a secondary form of osteoarthritic analysis.

Results

T2DM rats had higher mean osteoarthritis scores than the control rats in each of the four areas that were analysed. However, only the results at the medial and lateral femur and medial tibia were significant. Cysts were also found in T2DM rats at the junction of the articular cartilage and subchondral bone. Immunohistochemical analysis does not show an increase in collagen II between control and T2DM rats. Mass comparisons also showed a significant relationship between mass and osteoarthritis score.

Conclusions

T2DM was found to cause global degeneration in the UCD rat knee joints, suggesting that diabetes itself is a factor in the onset and progression of osteoarthritis. The immunohistochemistry stains showed little to no change in collagen II degeneration between T2DM and control rats. Overall, it seems that the animal model used is pertinent to future studies of T2DM in the development and progression of osteoarthritis.

Cite this article: Bone Joint Res 2014;3:203–11

Co-administration of hyaluronic acid with local anaesthetics shows lower cytotoxicity than local anaesthetic treatment alone in bovine articular chondrocytes

OBJECTIVE

To study the effect of hyaluronic acid (HA) on local anaesthetic chondrotoxicity in vitro.

METHODS

Chondrocytes were harvested from bovine femoral condyle cartilage and isolated using collagenase-containing media. At 24 hours after seeding 15 000 cells per well onto a 96-well plate, chondrocytes were treated with media (DMEM/F12 + ITS), PBS, 1:1 lidocaine (2%):PBS, 1:1 bupivacaine (0.5%):PBS, 1:1 lidocaine (2%):HA, 1:1 bupivacaine (0. 5%):HA, or 1:1 HA:PBS for one hour. Following treatment, groups had conditions removed and 24-hour incubation. Cell viability was assessed using PrestoBlue and confirmed visually using fluorescence microscopy.

RESULTS

Media-treated groups had a mean of 1.55×10(4) cells/well (sem 783). All treated cells showed statistically significant reduced viability when compared with media alone (all p < 0.003). Cells treated with bupivacaine + HA (6.70×10(3) cells/well (sem 1.10×10(3))) survived significantly more than bupivacaine (2.44×10(3) cells/well (sem 830)) (p < 0.001). Lidocaine + HA (1.45×10(3) cells/well (sem 596)) was not significantly more cytotoxic than lidocaine (2.24×10(3) cells/well (sem 341)) (p = 0.999). There was no statistical difference between the chondrotoxicities of PBS (8.49×10(3) cells/well (sem 730) cells/well) and HA (4.75×10(3) cells/well (sem 886)) (p = 0.294).

CONCLUSIONS

HA co-administration reduced anaesthetic cytotoxicity with bupivacaine but not lidocaine, suggesting different mechanisms of injury between the two. Co-administered intra-articular injections of HA with bupivacaine, but not lidocaine, may protect articular chondrocytes from local anaesthetic-associated death. Cite this article: Bone Joint Res 2013;2:270-5.

Strategies for the synthesis of thermoplastic polymer nanocomposite materials with high inorganic filling fraction

The governing parameters controlling the miscibility of particle additives within polymeric host media are analyzed for the particular case of silica particle fillers embedded within a poly(methyl methacrylate) (PMMA) matrix. For athermal polymer-graft modification of particles (corresponding to equal chemical composition of graft and matrix polymer), compatibility is found to be a sensitive function of the degree of polymerization of graft and host polymer chains as well as the particle radius. In agreement with theoretical predictions, uniform particle dispersion is observed if the degree of polymerization of grafted chains is comparable to (or exceeds) the corresponding value of the polymer matrix. The resulting restriction to high degree of polymerization limits the accessible inorganic fraction that is attainable in athermal particle/polymer blends. In contrast, favorable interaction between grafted polymer chains and the polymeric host (as realized in the case of poly(styrene-r-acrylonitrile)-grafted particles embedded within PMMA matrix) is shown to facilitate thermodynamically stable and uniform particle dispersion across the entire compositional range even in the limit of large particle size, short grafted chains, and high molecular matrix chains. The synthesis of thermoplastic composite materials with inorganic fraction exceeding 50 vol % combining quantitative optical limiting within the UV frequency range and polymer-like mechanical properties is demonstrated.

18-FDG-PET in assessing disease activity in Takayasu arteritis: a meta-analysis

OBJECTIVES

To assess the diagnosis value of 18-FDG-PET in estimating disease activity in Takayasu arteritis.

METHODS

A complete search of PubMed, EMBASE and The Cochrane Library was finished to July 25, 2012. Sensitivity and specificity as well as pooled estimates of positive and negative likelihood ratios (PLR and NLR) were calculated by Meta-Disc. We also calculated the area under the sROC curve (AUC) and the Q* index.

RESULTS

The meta-analysis was finished with 6 study retrieved from the database search. The pooled sensitivity, and specificity with 95% confidence interval were 70.1% (95% CI, 58.6-80.0) and 77.2% (95% CI, 64.2-87.3). The PLR and NLR were 2.313 (95% CI 1.108-4.829) and 0.341 (95% CI 0.142-0.824). The AUC was 0.805(±0.084) and Q* index was 0.7402 (±0.0739).

CONCLUSIONS

18-FDG-PET had moderate diagnosis value in assessing TA activity. It may add additional value to the current diagnosis methods.

A phylogenetic analysis of the genus Pleurothallis, with emphasis on Pleurothallis subsection Macrophyllae-Fasciculatae, using nuclear ITS and chloroplast DNA sequencing

Several revisions of the genus Pleurothallis have been proposed. Luer has proposed that Pleurothallis species in subgenus Scopula be segregated into the genera Colombiana and Ancipitia. Szlachetko and Margonska (2001) proposed the genus Zosterophyllanthos for Pleurothallis subsection Macrophyllae-Fasciculatae. As an alternative, Luer (2005) proposed the genus Acronia by uniting Pleurothallis subsection Macrophyllae-Fasciculatae with subsections Acroniae and Amphygiae. The molecular phylogenetic studies by Pridgeon and Chase (2001), however, suggested that these taxonomic revisions might not be justified. We report here a more detailed phylogenetic analysis of the genus Pleurothallis, with emphasis on subsection Macrophyllae-Fasciculatae, with data primarily from nuclear ITS sequencing, supplemented with preliminary data from plastid DNA (rpoB2, rpoC1, and ycf1) sequencing. Some initial, tentative conclusions can be drawn. In the strict consensus maximum-parsimony tree of ITS data, many of the clades collapse, leaving a polytomy with a single, highly supported node that tentatively could be used to delimit the genus Pleurothallis. Such a tree would argue for an expanded concept of the genus Pleurothallis, in which the groups Ancipitia, Colombiana, and Acronia/Zosterophyllanthos, if shown to be monophyletic, are relegated to subgenera. 

Staphylococcal toxic shock syndrome

A 28 year old male presented with fever, tachycardia, generalized lymphadenopathy and diffuse rash over the body. He failed to respond to intravenous antibiotics and developed cardiogenic shock, multiple organ failure and died within six hours after hospitalization. Staphylococcus aureus colonies were revealed on blood culture.