High-strength, anti-fatigue, cellulose nanofiber reinforced polyvinyl alcohol based ionic conductive hydrogels for flexible strain/pressure sensors and triboelectric nanogenerators.

Ionic conductive hydrogels (ICHs) have attracted great attention because of their excellent biocompatibility and structural similarity with biological tissues. However, it is still a huge challenge to prepare a high strength, conductivity and durability hydrogel-based flexible sensor with dual network structure through a simple and environmentally friendly method. In this work, a simple one-pot cycle freezing thawing method was proposed to prepare ICHs by dissolving polyvinyl alcohol (PVA) and ferric chloride (FeCl3) in cellulose nanofiber (CNF) aqueous dispersion. A dual cross-linked network was established in hydrogel through the hydrogen bonds and coordination bonds among PVA, CNF, and FeCl3. This structure endows the as-prepared hydrogel with high sensitivity (pressure sensitivity coefficient (S) = 5.326 in the pressure range of 0-5 kPa), wide response range (4511 kPa), excellent durability (over 3000 cycles), short response time (83 ms) and recovery time (117 ms), which can accurately detect various human activities in real time. Furthermore, the triboelectric nano-generator (TENG) made from PVA@CNF-FeCl3 hydrogel can not only supply power for commercial capacitors and LED lamps, but also be used as a self-powered sensor to detect human motion. This work provides a new approach for the development of the next generation of flexible wearable electronic devices.

Green technology innovation and carbon emission efficiency: The moderating role of environmental uncertainty.

Given the significant global warming caused by large-scale carbon emissions, it has become a crucial issue affecting human survival and world development. As a supportive means for relevant policies, the implementation of green technology innovation is essential for effectively achieving dual carbon goals. In order to explore the intrinsic relationship and impact mechanism between green technology innovation and carbon emission efficiency, this study takes data from high-energy-consuming manufacturing companies listed on the A-share market in China from 2010 to 2019 as samples. It uses the Super-SBM model to measure the carbon emission efficiency of sample companies and employs a two-way fixed effects model to verify the impact of green technology innovation on the carbon emission efficiency of high-energy-consuming manufacturing enterprises. Furthermore, this study also explores the external mechanism of green technology innovation related to carbon emission efficiency, focusing on the moderating variable of environmental uncertainty. The study found that both the quantity and quality of green technology innovation can significantly promote the carbon emission efficiency of high-energy-consuming manufacturing enterprises, and the accuracy of the results remains unchanged after conducting robustness tests. Environmental uncertainty plays an important role in moderating the process of green technology innovation, affecting the carbon emission efficiency of high-energy-consuming manufacturing enterprises. Heterogeneity tests show that the impact of green technology innovation on carbon emission efficiency is particularly significant in the central region and in enterprises experiencing decline. The policy implications derived from empirical analysis aim to provide empirical evidence for promoting the high-quality development of China's high-energy-consuming manufacturing enterprises.

Enhancing the energetic and magnetic stability of atomic hydrogen chemisorbed on graphene using (non)compensated B-N pairs.

In this pioneering study for identifying atomic scale magnetic moment, a single hydrogen atom chemisorbed on pristine graphene exhibits distinct spin polarization. Using first-principles calculations and analyses, we demonstrate that the binding between a H adsorbate and a C substrate is substantially enhanced via compensated B-N pairs embedded into graphene. Surprisingly, the interaction can be further enhanced via non-compensated B-N pair doping. Our established prototype of orbital intercoupling between H 1s and hybridized pz of gapped band edges gives an insight into the enhancing mechanism. For compensated B-N doping, the conduction band minimum (CBM) is pushed upward, which induces stronger interaction between the H 1s and hybridized pz orbitals of the CBM. For non-compensated B-N doping, the orbital interaction occurs between H 1s and hybridized pz orbitals of valence band maximum, thus further lowering the resulting bonding energy due to the enlarged gap. This significantly enhanced interaction between H and C atoms agrees well with the results of charge localization at the gapped band edges. More importantly, the corresponding magnetic moments can be well maintained or even enhanced in both doping; here, one more H atom is needed for non-compensated doping, where its electron occupies the empty CBM. Our findings might provide an effective and practical way to enhance the energetic and magnetic stability of atomic scale magnetic moment on graphene and extensively expand the conception of non-compensated doping.

MnO2 porous carbon composite from cellulose enabling high gravimetric/volumetric performance for supercapacitor.

Preparing electrode material integrated with high gravimetric/volumetric capacitance and fast electron/ion transfer is crucial for the practical application. Owing to the structural contradiction, it is a big challenge to construct electrode material with high packing density, sufficient ion transport channels, and fast electronic transfer pathways. Herein, MnO2 porous carbon composite with abundant porous structure and 3D carbon skeleton was facilely fabricated from Linum usitatissimum. L stems via NaOH activation and MnO2 introduction. The in-situ introduced MnO2 not only increases the packing density and the electrical conductivity of the porous carbon but also provides more active sites for oxidation reactions. These unique characteristics endow the resultant MnO2 porous carbon composite with remarkable gravimetric capacitance of 549 F g-1, volumetric capacitance of 378 F cm-3, and capacitance retention of 54.9 %. Giving the simple process and low cost, this work might offer a new approach for structural design and the practical application of high-performance electrode materials.

Spent Coffee Grounds Derived Carbon Loading C, N Doped TiO2 for Photocatalytic Degradation of Organic Dyes.

Titanium dioxide (TiO2) is an ideal photocatalyst candidate due to its high activity, low toxicity and cost, and high chemical stability. However, its practical application in photocatalysis is seriously hindered by the wide band gap energy of TiO2 and the prone recombination of electron-hole pairs. In this study, C, N doped TiO2 were supported on spent coffee grounds-derived carbon (ACG) via in situ formation, which was denoted as C, N-TiO2@ACG. The obtained C, N-TiO2@ACG exhibits increased light absorption efficiency with the band gap energy decreasing from 3.31 eV of TiO2 to 2.34 eV, a higher specific surface area of 145.8 m2/g, and reduced recombination rates attributed to the synergistic effect of a spent coffee grounds-derived carbon substrate and C, N doping. Consequently, the optimal 1:1 C, N-TiO2@ACG delivers considerable photocatalytic activity with degradation efficiencies for methylene blue (MB) reaching 96.9% within 45 min, as well as a high reaction rate of 0.06348 min-1, approximately 4.66 times that of TiO2 (0.01361 min-1). Furthermore, it also demonstrated greatly enhanced photocatalytic efficiency towards methyl orange (MO) in the presence of MB compared with a single MO solution. This work provides a feasible and universal strategy of synchronous introducing nonmetal doping and biomass-derived carbon substrates to promote the photocatalytic performance of TiO2 for the degradation of organic dyes.

MOF-Derived Co/C and MXene co-Decorated Cellulose-Derived Hybrid Carbon Aerogel with a Multi-Interface Architecture toward Absorption-Dominated Ultra-Efficient Electromagnetic Interference Shielding.

Exploring electromagnetic interference (EMI) shielding materials with ultra-efficient EMI shielding effectiveness (SE) and an absorption-dominated mechanism is urgently required for fundamentally tackling EMI radiation pollution. Herein, zeolitic imidazolate framework-67 (ZIF-67)/MXene/cellulose aerogels were first prepared via a simple solution mixing-regeneration and freeze-drying process. Subsequently, they are converted into electric/magnetic hybrid carbon aerogels (Co/C/MXene/cellulose-derived carbon aerogels) through a facile pyrolysis strategy. ZIF-67-derived porous Co/C could provide the additional magnetic loss capacity. The resultant electric/magnetic hybrid carbon aerogels exhibit a hierarchically porous structure, complementary electromagnetic waves (EMWs) loss mechanisms, and abundant heterointerfaces. The construction of a porous architecture and the synergy of electric/magnetic loss could greatly alleviate the impedance mismatching at the air-specimen interface, which enables more EMWs to enter into the materials for consumption. Moreover, numerous heterointerfaces among Co/C, Ti3C2Tx MXene, and cellulose-derived carbon skeleton induce the generation of multiple polarization losses containing interfacial and dipole polarization, which further dissipate the EMWs. The resultant electric/magnetic hybrid carbon aerogel with a low density (85.6 mg/cm3) achieves an ultrahigh EMI SE of 86.7 dB and a superior absorption coefficient of 0.72 simultaneously. This work not only offers a novel approach to design high-performance EMI shielding materials entailing low reflection characteristic but also broadens the applicability of electric/magnetic hybrid carbon aerogels in aerospace, precision electronic devices, and military stealth instruments.

Multifunctional CoFe2O4@MXene-AgNWs/Cellulose Nanofiber Composite Films with Asymmetric Layered Architecture for High-Efficiency Electromagnetic Interference Shielding and Remarkable Thermal Management Capability.

Developing high-efficiency electromagnetic interference (EMI) shielding composite films with outstanding flexibility and excellent thermal management capability is vital but challenging for modern integrated electronic devices. Herein, a facile two-step vacuum filtration method was used to fabricate ultrathin, flexible, and multifunctional cellulose nanofiber (CNF)-based composite films with an asymmetric layered architecture. The asymmetric layered structure is composed of a low-conductivity CoFe2O4@MXene/CNF layer and a highly conductive silver nanowires (AgNWs)/CNF layer. Benefiting from the rational placement of the impedance matching layer and shielding layer, as well as the synergistic effect of electric and magnetic losses, the resultant composite film exhibits an extremely high EMI shielding effectiveness (SE) of 73.3 dB and an average EMI SE of 70.9 dB with low reflected efficiency of 4.9 dB at only 0.1 mm thickness. Sufficiently reliable EMI SE (over 95% reservation) is attained even after suffering from continuous physical deformations and long-term chemical attacks. Moreover, the prepared films exhibit extraordinary flexibility, strong mechanical properties, and satisfactory thermal management capability. This work offers a viable strategy for exploiting high performance EMI shielding films with attractive thermal management capacity, and the resultant films present extensive application potential in aerospace, artificial intelligence, advanced electronics, stealth technology, and the national defense industry, even under harsh environments.

Facile construction of core-shell Carbon@CoNiO2 derived from yeast for broadband and high-efficiency microwave absorption.

Manufacturing dielectric/magnetic composites with hierarchical structure is regard as a promising strategy for the progress of high-performance microwave absorption (MA) materials. In this paper, the nano-grass structured CoNiO2 magnetic shell was uniformly anchored on the yeast-derived carbon microspheres by in-situ one-pot synthesis method. Profiting from the unique nano-grass and core-shell structure, capable dielectric/magnetic loss, along with improved impedance matching, the prepared absorber realizes desirable MA performance. The minimum reflection loss (RLmin) reaches up to -44.06 dB at 6.56 GHz. Moreover, the effective absorption bandwidth (EAB, reflection loss (RL) < -10 dB) accomplishes 7.04 GHz under a low filler loading of 20 wt%. This work endeavors a valuable insight for designing innovative core-shell structured materials with high-efficiency MA and broad bandwidth.

Three-dimensional macroporous hybrid carbon aerogel with heterogeneous structure derived from MXene/cellulose aerogel for absorption-dominant electromagnetic interference shielding and excellent thermal insulation performance.

The development of electromagnetic interference (EMI) shielding materials with excellent absorption coefficient (A) is vital to completely eliminate the pollution of the ever-increasing electromagnetic waves (EMWs). In this regard, a TiC/carbon hybrid aerogel, derived from MXene/cellulose aerogel, was successfully fabricated via freeze-drying and subsequent pyrolysis process. Profiting from the open, loose three-dimensional (3D) macro pores with sheet-like morphology and high porosity, as well as the rich heterogeneous interfaces between TiC and cellulose-derived carbon, the as-prepared hybrid carbon aerogel achieves ultra-efficient EMI shielding effectiveness of 72.9 dB in conjunction with a superior A value of 0.76 and low thermal conductivity. These properties endow the as-prepared aerogel with strong absorption-dominant ultra-efficient EMI shielding and thermal insulation performance to meet the complex practical requirements. This work provides a promising strategy for achieving ultra-efficient multifunctional EMI shielding performance and superior A simultaneously.

Magnetic coupling N self-doped porous carbon derived from biomass with broad absorption bandwidth and high-efficiency microwave absorption.

Nowadays, developing microwave absorption materials (MAMs) with thin thickness, wide-frequency effective absorption bandwidth (EAB) and strong absorbing capacity is an urgent requirement to tackle the increasingly serious electromagnetic radiation issue. Herein, we report a novel high-performance MAMs by growing Fe3O4 nanoparticles on activated porous carbon derived from egg white via a facile carbonization and subsequent hydrothermal approach. The resultant composite features three-dimensional hierarchical porous carbon embedded with Fe3O4 nanoparticles. Benefiting from the balanced impedance matching and the multi-loss that involve the conductive loss, dielectric loss, dipolar/interfacial polarization loss and magnetic loss, the prepared composite achieves a minimum reflection loss (RL) of -43.7 dB at 9.92 GHz and a broad EAB (RL < -10 dB) of 7.52 GHz (6.24-13.76 GHz) at a thin thickness of 2.5 mm and a low filler content of 20 wt%. This work provides new insights for exploring novel magnetic coupling porous carbon derived from biomass with high-efficiency microwave absorption performance.

Flexible and Anisotropic Strain Sensors with the Asymmetrical Cross-Conducting Network for Versatile Bio-Mechanical Signal Recognition.

Flexible strain sensors with high performance are actively and widely investigated for wearable electronic devices. However, the conventional sensors often suffer from a lack of detection of complex multidimensional strain, which severely limits their wide applications. To overcome this critical challenge, we propose a pattern design by screen printing to construct an asymmetrical cross-conductive network in the piezoresistive strain sensor, which can enhance the response to external stimuli in different directions. The unique network endows the prepared sensors with the excellent ability of instantaneous detection and accurate identification of multidimensional strains. Moreover, the sensor also demonstrates high sensitivity, fast response, an ultra-wide sensing range, and excellent stability and durability. Benefiting from the outstanding comprehensive performance of the prepared sensor, a full range of human actions (wink, smile, swallowing, and joint bending) and subtle bio-signals (pulse and breathing) are easily and accurately monitored. A wireless wearable device assembled by the sensor shows great potential applications in practical real-time physiological monitoring and intelligent mobile diagnosis for humans. This work provides an innovative and effective strategy for manufacturing flexible and multifunctional strain sensors to fully satisfy versatile applications of new-generation wearable electronic devices.

Impact of Dexmedetomidine on Intraoperative Wake-Up Tests in Patients Undergoing Spinal Surgery.

PURPOSE: To evaluate the impact of dexmedetomidine (DEX) on intraoperative wake-up tests. DESIGN: American Society of Anesthesiologists category I or II patients were divided into two groups: a propofol-remifentanil group (group R, n = 20) and a DEX-propofol-remifentanil group (group D, n = 20). METHODS: The patients in group D received DEX, whereas the patients in group R received the same volume of saline. The other anesthetic methods and drugs (propofol and remifentanil) were the same in both groups. During the wake-up test, patients were repeatedly asked to move their fingers. FINDINGS: All the wake-up tests were successfully performed. There was no significant difference in the mean wake-up time between the two groups. Eighteen patients exhibited better wake-up quality in group D as did eight patients in group R. The patients in group D had a significantly better overall wake-up quality than those in group R (P <.05). CONCLUSIONS: DEX did not affect the wake-up time and increased the wake-up quality.

Amino Functionalization of Reduced Graphene Oxide/Tungsten Disulfide Hybrids and Their Bismaleimide Composites with Enhanced Mechanical Properties.

A novel graphene-based nanocomposite particles (NH2-rGO/WS2), composed of reduced graphene oxide (rGO) and tungsten disulfide (WS2) grafted with active amino groups (NH2-rGO/WS2), was successfully synthesized by an effective and facile method. NH2-rGO/WS2 nanoparticles were then used to fabricate new bismaleimide (BMI) composites (NH2-rGO/WS2/BMI) via a casting method. The results demonstrated that a suitable amount of NH2-rGO/WS2 nanoparticles significantly improved the mechanical properties of the BMI resin. When the loading of NH2-rGO/WS2 was only 0.6 wt %, the impact and flexural strength of the composites increased by 91.3% and 62.6%, respectively, compared to the neat BMI resin. Rare studies have reported such tremendous enhancements on the mechanical properties of the BMI resin with trace amounts of fillers. This is attributable to the unique layered structure of NH2-rGO/WS2 nanoparticles, fine interfacial adhesion, and uniform dispersion of NH2-rGO/WS2 in the BMI resin. Besides, the thermal gravimetrical analysis (TGA) revealed that the addition of NH2-rGO/WS2 could also improve the stability of the composites.

Space-confined synthesis of multilayer Cu-N-doped graphene nanosheets for efficient oxygen electroreduction.

Cu-based carbon electrocatalysts for the oxygen reduction reaction are difficult to compare with the corresponding Fe- or Co-based electrocatalytic materials, owing to their insufficient catalytic activity and stability. Herein, as an impressive Cu-based electrocatalyst, a multilayer Cu-N-doped graphene sheet (Cu-N-GR) is directly synthesized by the thermal conversion of copper(ii) 2,2'-bipyridine in the confined space of lamellar montmorillonites. The open layered morphology of Cu-N-GR materials facilitated the exposure of more active centers and enhanced the flexibility and mobility of charge carriers. Combining the unique electronic properties of layered morphology and the synergistic effect of Cu and N, the obtained Cu-N-GR exhibits surprising results in terms of ORR catalytic activity, particularly in catalytic stability and methanol-tolerant properties in alkaline media.

Imidazolium Ionic Liquid Modified Graphene Oxide: As a Reinforcing Filler and Catalyst in Epoxy Resin.

Surface modification of graphene oxide (GO) is one of the most important issues to produce high performance GO/epoxy composites. In this paper, the imidazole ionic liquid (IMD-Si) was introduced onto the surface of GO sheets by a cheap and simple method, to prepare a reinforcing filler, as well as a catalyst in epoxy resin. The interlayer spacing of GO sheets was obviously increased by the intercalation of IMD-Si, which strongly facilitated the dispersibility of graphene oxide in organic solvents and epoxy matrix. The addition of 0.4 wt % imidazolium ionic liquid modified graphene oxide (IMD-Si@GO), yielded a 12% increase in flexural strength (141.3 MPa), a 26% increase in flexural modulus (4.69 GPa), and a 52% increase in impact strength (18.7 kJ/m²), compared to the neat epoxy. Additionally the IMD-Si@GO sheets could catalyze the curing reaction of epoxy resin-anhydride system significantly. Moreover, the improved thermal conductivities and thermal stabilities of epoxy composites filled with IMD-Si@GO were also demonstrated.

Water-Soluble Blue Fluorescence-Emitting Hyperbranched Polysiloxanes Simultaneously Containing Hydroxyl and Primary Amine Groups.

In this Communication, novel water-soluble hyperbranched polysiloxanes (WHPSs) simultaneously containing hydroxyl and primary amine groups are developed. The polymers are constructed via melt polycondensation, that is, transesterification reaction between ethoxyl groups of (3-aminopropyl)triethoxysilane and hydroxyl groups of dihydric alcohols, using a one-step process under catalyst-free conditions. Surprisingly, the resultant WHPSs can emit bright blue fluorescence in the 100% solid state under the irradiation of UV light, and their photoluminescence intensities in aqueous solutions continuously go up along with increasing concentrations. Interestingly, their hydrolyzates display more intense luminescence compared to the unhydrolyzed. The efficient and easily controllable preparation strategy provides a remarkable and versatile platform for the fabrication of neoteric fluorescent materials for various potential applications.

Confirmation of three inflammatory bowel disease susceptibility loci in a Chinese cohort.

PURPOSE: Recent genome-wide association studies have identified a number of inflammatory bowel diseases (IBD) susceptibility loci in White populations. The aim of our study was to evaluate whether these susceptibility loci also existed in a Chinese Han IBD population. METHODS: Peripheral blood DNA samples from groups of patients with Crohn's disease (CD) (n = 48), ulcerative colitis (UC) (n = 49), and healthy controls (n = 50) were genotyped for eight genes. Then, an extended analysis of the relationship between genotype and phenotype was performed. RESULTS: NOD2-P268S (P = 0.025) was found to contribute susceptibility to CD in the Chinese population. IL23R-rs11805303 was detected to confer a strong protective effect against UC (P = 0.010), whereas PTPN2-rs2542151 was significantly associated with an increased risk of UC (P = 0.001). Further phenotype-genotype analysis revealed that P268S was associated with early age of onset (P = 0.028), ileal disease (P = 0.003), and enteric cavity narrowing (P = 0.007). CONCLUSIONS: The study indicates that IL23R-rs11805303 and PTPN2-rs2542151 might contribute to the development of UC and NOD2-P268S might be involved in the etiology of CD in the Chinese Han population.

High-relaxivity MRI contrast agents prepared from miniemulsion polymerization using gadolinium(III)-based metallosurfactants.

Miniemulsion polymerization with amphiphilic gadolinium(III) complexes as metallosurfactants was explored as a new technique for the synthesis of high relaxivity MRI contrast agents. Well-defined metallo-colloids with up to 240% enhancement in relaxivity over their small molecular counterparts were obtained.

[Correlation of the autophagosome gene ATG16L1 polymorphism and inflammatory bowel disease].

OBJECTIVE: To understand the relationship between the susceptibility to inflammatory bowel disease (IBD) and ATG16L1 gene single nucleotide polymorphism (SNP) site, rs2241880. METHODS: Peripheral blood samples were collected from 80 IBD patients (including 40 with Crohn's disease and 40 with ulcerative colitis) and 50 healthy controls, and the genomic DNA was extracted from the white blood cells. Specific primers were designed according to the target gene sequence for PCR amplification of the target gene fragment, and the PCR products were purified followed by sequence analysis of the target region of ATG16L1 gene. The results of the sequence analysis were compared with the BenBank data to analyze the relationship between the allele gene polymorphisms and the susceptibility to Crohn's disease. RESULTS: No significant differences were noted in the ATG16L1 gene SNP site rs2241880 polymorphisms among the patients with Crohn's disease, ulcerative colitis and the control subjects (Chi(2)=4.94, P=0.293). CONCLUSION: ATG16L1 gene polymorphisms in the SNP site rs2241880 are not found to correlate to the susceptibility to Crohn's disease as reported in literature. The SNP site associated with Crohn's disease susceptibility identified in foreign populations does not seem to be identical with that in Chinese population.